Can the mirror created by reflector.js be set to receive shadows

 const mirrorGeometry = new THREE.PlaneBufferGeometry(1000, 400);
        const mirrorOptions = {
            clipBias: 0.03,
            textureWidth: window.innerWidth * window.devicePixelRatio,
            textureHeight: window.innerHeight * window.devicePixelRatio,
        const mirror = new THREE.Reflector(mirrorGeometry, mirrorOptions);
        mirror.receiveShadow = true; // 设置接受阴影

The object that produces the shadow has been set “castShadow = true”, The above “receiveShadow” Settings do not take effect

In my example : Reflector (, the shadows are in the mirror (reflector) without setting anything specific on the mirror.

Check that shadows work in your scene, before checking the reflection. Ensure you have shadowMap enabled for your renderer, and your objects are receiving/casting shadows appropriately.

The shadow of this example should be received by the ground, then the shadow seen in the mirror is the shadow cast by the character on it. The effect I want is that when the character is close to the mirror, the shadow of the character will be partially refracted to the mirror

I understand now. You want the scenes lights to bounce of the mirror and also cast shadows in the main scene. These extra shadows would already be present in the reflector if you were able to produce it.
You probably want some kind of raytracing solution. Probably Screen Space Reflection (