求帮解决这是什么原因啊

类型“void”上不存在属性“children”

    attackEnemy(){
    let node=find('Canvas/bg/Enemies');
    let enemies=node.children;
    if(enemies){
        for(let enemy of enemies){
            if(enemy){
                let pPos=this.node.position;
                let ePos=enemy.position;
                if(Vec2.distance(ePos,pPos)<=25){
                    let enemyScript=enemy.getComponent('Enemy')as Enemy;
                    if(enemyScript){
                        if(enemyScript.getEnemyState()!=4){
                            enemyScript.setEnemyState(3);
                        }
                    }
                }
            }

        }
    }
}