针对等值线迭代最近点算法(ICCP)在大的初始位置误差下易发散的问题,提出利用价值函数等值线算法对初始位置进行调优;针对该算法在旋转与平移变换过程中存在误差传播的问题,提出在最近点附近对ICCP算法进行加密的改进方法.在初始匹配误差为3.5′下进行仿真实验,结果证明:利用加密的改进ICCP算法得到了最终匹配位置,提高了传统ICCP算法的精度;即使是在大的初始匹配误差下仍能达到很高的定位精度. Aiming at the problem that the ICCP is easy to diverge under the large initial position error, this paper proposes the use of the isoline function of the value function to tune the initial position. In view of the error of the algorithm in the rotation and translation process And proposes an improved method of encrypting the ICCP algorithm near the nearest point.After the initial matching error is 3.5 ’, the simulation results show that the final matching position is obtained by using the improved ICCP algorithm and the traditional ICCP algorithm is improved Accuracy; even in large initial matching error can still achieve high positioning accuracy.