1.新建脚本，并将脚本拖到你想要拖动的物体上即可

using System.Collections;
using System.Collections.Generic;
using Unity.VisualScripting;
using UnityEngine;

public class text : MonoBehaviour
{
    private Vector3 offset;
    public int x = 1;
    void OnMouseDown()//鼠标按下
    {
        offset = transform.position - Camera.main.ScreenToWorldPoint(Input.mousePosition);
    }
    void OnMouseDrag()//鼠标持续按下
    {
        Vector3 newPosition = Camera.main.ScreenToWorldPoint(Input.mousePosition) + offset;
        transform.position = new Vector3(newPosition.x, newPosition.y, transform.position.z);
    }
}