diff --git a/apisix/cli/file.lua b/apisix/cli/file.lua
index 36873631a84c..28412de286d6 100644
--- a/apisix/cli/file.lua
+++ b/apisix/cli/file.lua
@@ -90,7 +90,10 @@ local function var_sub(val)
 end
 
 
-local function resolve_conf_var(conf)
+local function resolve_conf_var(conf, enable_type_conversion)
+    if enable_type_conversion == nil then
+        enable_type_conversion = true
+    end
     local new_keys = {}
     for key, val in pairs(conf) do
         -- avoid re-iterating the table for already iterated key
@@ -111,7 +114,7 @@ local function resolve_conf_var(conf)
             end
         end
         if type(val) == "table" then
-            local ok, err = resolve_conf_var(val)
+            local ok, err = resolve_conf_var(val, enable_type_conversion)
             if not ok then
                 return nil, err
             end
@@ -123,7 +126,7 @@ local function resolve_conf_var(conf)
                 return nil, err
             end
 
-            if var_used then
+            if var_used and enable_type_conversion then
                 if tonumber(new_val) ~= nil then
                     new_val = tonumber(new_val)
                 elseif new_val == "true" then
@@ -255,7 +258,7 @@ function _M.read_yaml_conf(apisix_home)
             return nil, "invalid config.yaml file"
         end
 
-        local ok, err = resolve_conf_var(user_conf)
+        local ok, err = resolve_conf_var(user_conf, true)
         if not ok then
             return nil, err
         end
@@ -304,7 +307,7 @@ function _M.read_yaml_conf(apisix_home)
         if apisix_conf_yaml then
             local apisix_conf = yaml.load(apisix_conf_yaml)
             if apisix_conf then
-                local ok, err = resolve_conf_var(apisix_conf)
+                local ok, err = resolve_conf_var(apisix_conf, false)
                 if not ok then
                     return nil, err
                 end
diff --git a/apisix/core/config_yaml.lua b/apisix/core/config_yaml.lua
index d0443f256f43..188c3fce3cf2 100644
--- a/apisix/core/config_yaml.lua
+++ b/apisix/core/config_yaml.lua
@@ -153,7 +153,7 @@ local function update_config(table, conf_version)
         return
     end
 
-    local ok, err = file.resolve_conf_var(table)
+    local ok, err = file.resolve_conf_var(table, false)
     if not ok then
         log.error("failed to resolve variables:" .. err)
         return
diff --git a/t/cli/test_standalone.sh b/t/cli/test_standalone.sh
index d5844a2ce654..a575368e5c29 100755
--- a/t/cli/test_standalone.sh
+++ b/t/cli/test_standalone.sh
@@ -155,3 +155,142 @@ if [ $expected_config_reloads -ne $actual_config_reloads ]; then
     exit 1
 fi
 echo "passed: apisix.yaml was not reloaded"
+
+make stop
+sleep 0.5
+
+# test: environment variable with large number should be preserved as string
+echo '
+apisix:
+  enable_admin: false
+deployment:
+  role: data_plane
+  role_data_plane:
+    config_provider: yaml
+' > conf/config.yaml
+
+echo '
+routes:
+  -
+    uri: /test-large-number
+    plugins:
+      response-rewrite:
+        body: "${{APISIX_CLIENT_ID}}"
+        status_code: 200
+    upstream:
+      nodes:
+        "127.0.0.1:9091": 1
+      type: roundrobin
+#END
+' > conf/apisix.yaml
+
+# Test with large number that exceeds Lua double precision
+APISIX_CLIENT_ID="356002209726529540" make init
+
+if ! APISIX_CLIENT_ID="356002209726529540" make run > output.log 2>&1; then
+    cat output.log
+    echo "failed: large number in env var should not cause type conversion error"
+    exit 1
+fi
+
+sleep 0.1
+
+# Verify the response body matches the exact large numeric string
+code=$(curl -o /tmp/response_body -s -m 5 -w %{http_code} http://127.0.0.1:9080/test-large-number)
+body=$(cat /tmp/response_body)
+if [ "$code" -ne 200 ]; then
+    echo "failed: expected 200 for /test-large-number, but got: $code, body: $body"
+    exit 1
+fi
+if [ "$body" != "356002209726529540" ]; then
+    echo "failed: large number env var was not preserved as string, got: $body"
+    exit 1
+fi
+
+make stop
+sleep 0.5
+
+echo "passed: large number in env var preserved as string in apisix.yaml"
+
+# test: quoted numeric env vars in apisix.yaml should remain strings
+echo '
+apisix:
+  enable_admin: false
+deployment:
+  role: data_plane
+  role_data_plane:
+    config_provider: yaml
+' > conf/config.yaml
+
+echo '
+routes:
+  -
+    uri: /test-quoted
+    plugins:
+      response-rewrite:
+        body: "${{NUMERIC_ID}}"
+        status_code: 200
+    upstream:
+      nodes:
+        "127.0.0.1:9091": 1
+      type: roundrobin
+#END
+' > conf/apisix.yaml
+
+NUMERIC_ID="12345" make init
+NUMERIC_ID="12345" make run
+sleep 0.1
+
+code=$(curl -o /tmp/response_body -s -m 5 -w %{http_code} http://127.0.0.1:9080/test-quoted)
+body=$(cat /tmp/response_body)
+if [ "$code" -ne 200 ]; then
+    echo "failed: expected 200 for /test-quoted, but got: $code, body: $body"
+    exit 1
+fi
+if [ "$body" != "12345" ]; then
+    echo "failed: quoted numeric env var in apisix.yaml was not preserved as string, got: $body"
+    exit 1
+fi
+
+make stop
+sleep 0.5
+
+echo "passed: quoted numeric env var preserved as string in apisix.yaml"
+
+# test: config.yaml should still support type conversion (boolean)
+echo '
+routes: []
+#END
+' > conf/apisix.yaml
+
+echo '
+apisix:
+  enable_admin: ${{ENABLE_ADMIN}}
+deployment:
+  role: traditional
+  role_traditional:
+    config_provider: yaml
+  etcd:
+    host:
+      - "http://127.0.0.1:2379"
+' > conf/config.yaml
+
+ENABLE_ADMIN=false make init
+ENABLE_ADMIN=false make run
+sleep 0.1
+
+# If type conversion works, enable_admin is boolean false and admin API is disabled (404)
+# If type conversion fails, enable_admin stays string "false" which is truthy, admin API is enabled
+code=$(curl -o /dev/null -s -m 5 -w %{http_code} http://127.0.0.1:9080/apisix/admin/routes)
+if [ "$code" -ne 404 ]; then
+    echo "failed: expected 404 when admin API is disabled, but got: $code"
+    exit 1
+fi
+
+make stop
+sleep 0.5
+
+echo "passed: config.yaml still converts boolean env vars correctly"
+
+git checkout conf/config.yaml
+git checkout conf/apisix.yaml