In the field of industrial robot automatic welding,the transplanting clamping mechanism which realizes the joint welding of welding parts and welding gun plays an important role in the welding process.Usually in the industrial field,the shape of welding parts and welding conditions are very different,so it is necessary to design special fixture.In order to solve the clamping problem of cylindrical workpiece,a flexible clamping transplanting mechanism with inner wall was designed.It was applied to the welding condition of multi-manipulator with visual aid.The welding parts could be accurately transplanted to the designated welding position,and automatic welding could be realized in collaboration with welding robot.The transplanting clamping mechanism was designed,the statics simulation was carried out to verify the correctness of the model,and finally the physical verification environment was built for the clamping experiment.The experimental results show that the placement success rate of the first stage experiment is 100%, the transplanting mechanism meets the accuracy requirement of 2 mm welding distance in the second stage experiment,which provides good conditions for the transplanting of the head nozzle and it is conducive to the automatic welding of the head nozzle.