一：实现效果

二：第一种实现方法——弧形插值

using UnityEngine;

public class ArcMove : MonoBehaviour
{
    public GameObject curGo;//当前物体
    public GameObject targetGo;//目标物体

    public float value;

    private void Update()
    {
        //计算中心点  
        Vector3 center = (curGo.transform.position + targetGo.transform.position) / 2;

        center -= new Vector3(0, value, 0);

        Vector3 start = curGo.transform.position - center;
        Vector3 end = targetGo.transform.position - center;

        //弧形插值  
        curGo.transform.position = Vector3.Slerp(start, end, Time.time / 200);
        curGo.transform.position += center;

        //判定是否到达目标点
        float dis = Vector3.Distance(curGo.transform.position, targetGo.transform.position);
        if (dis <= 1)
        {
            Debug.Log("到达目标点");
        }
    }
}

三：第二种实现方法——计算弧线中的夹角

using UnityEngine;
using System.Collections;

public class ArcMove : MonoBehaviour
{
    public GameObject curGo;//当前物体
    public GameObject targetGo;//目标物体

    public float speed = 2;//速度  
    public int rotationAngle = 60;//旋转的角度

    private float distanceToTarget;//两者之间的距离  
    private bool move = true;//是否移动

    void Start()
    {
        //计算两者之间的距离  
        distanceToTarget = Vector3.Distance(curGo.transform.position, targetGo.transform.position);

        StartCoroutine(Move());
    }

    /// <summary>
    /// 移动
    /// </summary>
    private IEnumerator Move()
    {
        //移动到目标点停止移动
        while (move)
        {
            Vector3 targetPos = targetGo.transform.position;
            targetPos.z = 0;

            //让它始终朝着目标
            curGo.transform.LookAt(targetPos);

            //计算弧线中的夹角
            float angle = Mathf.Min(1, Vector3.Distance(curGo.transform.position, targetPos) / distanceToTarget) * rotationAngle;
            curGo.transform.rotation = curGo.transform.rotation * Quaternion.Euler(Mathf.Clamp(-angle, -42, 42), 0, 0);
            float currentDist = Vector3.Distance(curGo.transform.position, targetGo.transform.position);
            if (currentDist < 0.5f)
            {
                move = false;
                Debug.Log("到达目标点");
            }
            curGo.transform.Translate(Vector3.forward * Mathf.Min(speed * Time.deltaTime, currentDist));
            yield return null;
        }
    }
}