Aiming at the problems of low efficiency,high labor intensity and inadequate personal safety in the maintenance process of live manual replacement of spacer rods,a four-wheel mobile live maintenance robot suitable for double-split transmission line spacer rod replacement was designed.Based on the analysis of the working environment and operation objects,the robot structure with a manipulator on each arm was designed and the optimal degrees of freedom was obtained;the key technology in the operation process was analyzed,and the robot operation motion planning for the old spacer rod disassembly and the new spacer rod installation was proposed;the 3D model of the robot virtual prototype was developed by using INVENTOR,and the kinematics model of the key state of the manipulator during operation was established;the kinematics simulation of the robot arm was carried out by using MATLAB.The results show that the designed robot virtual prototype meets the needs of live maintenance operation,and it can provide reference for the development of robot physical prototype.