5G signals can provide accurate relative range/angle measurement information for multiple UAVs,thereby improving their cooperative positioning accuracy when the satellite receiver is malfunctioning.However,the 5G communication clock of each node in the cooperation network is often asynchronous,which will greatly affect the accuracy of range/angle measurement information,thereby reducing the fusion performance.To solve the above problems,a multi-UAV cooperative positioning method based on 5G signal asynchronous clock error compensation is proposed.Firstly,a relative range measurement model based on 5G signal asynchronous clock errors is constructed,and the position observation equation of the follower UAVs is established by using relative range/angle measurement information and altimeter information.Based on this,the joint optimal estimation of the Inertial Navigation System (INS) errors of the follower UAVs and asynchronous clock errors is realized by designing an Iterative Extended Kalman Filter (IEKF),which improves the positioning accuracy of the follower UAVs.The simulation results show that,compared with the traditional method,the proposed method improves the horizontal positioning accuracy of the follower UAVs by 25.3%.