This paper focused on the path planning of dual-robot coordinated couple motion when the  tool end posture changed during the process of coordination. The method of replacing tool coordinate system of slave robot was proposed for offline slave robot path generation. The kinematics constraints analysis was presented at the beginning; then the steps and flow chart of the proposed method were illustrated; after that, a dualrobot experimental platform was estalbished; finally, the linear and circular coordianted couple motion with posture change were implemented. The analysis of results indicates that the proposed method,  effective and accurate.