import net.ccbluex.liquidbounce.features.module.Module;
import net.ccbluex.liquidbounce.features.module.ModuleCategory;
import net.ccbluex.liquidbounce.features.module.ModuleInfo;
import net.ccbluex.liquidbounce.value.ListValue;

/**
 * @author koitoyuu
 */
@ModuleInfo(name = "CustomCape",fakeName = "Custom Cape",array = false,description = "",category = ModuleCategory.RENDER)
public class CustomCape extends Module {
    public final ListValue cape = new ListValue("Cape",new String[] {"Cape1","Cape2"},"Cape1");
}

中文: 然后找到MixinNetworkPlayerInfo并映射locationCape;
English: Then find MixinNetworkPlayerInfo and map locationCape.

    @Shadow
    private ResourceLocation locationCape;

中文: 最后Mixin注入getLocationCape
English: Finally Mixin injects getLocationCape

    /**
     * @author koitoyuu
     */
    @Inject(method = "getLocationCape", cancellable = true, at = @At("HEAD"))
    public void injectCustomCape(CallbackInfoReturnable<ResourceLocation> cir) {
        CustomCape customCape = (CustomCape) LiquidBounce.moduleManager.getModule(CustomCape.class);

        if (customCape.getState()) {
            if (gameProfile.getId().equals(Minecraft.getMinecraft().getSession().getProfile().getId())) {
                ResourceLocation resourceLocation = new ResourceLocation("liquidbounce/capes/"+customCape.cape.get()+".png");
                cir.setReturnValue(resourceLocation);
                cir.cancel();
            }
        }
    }

别忘记在assets.minecraft.liquidbounce.capes放入cape文件
Don't forget to put cape file in assets.minecraft.liquidbounce.capes