In some scenarios,the popular measurement software can not automatically generate the correct path by the “teach-by-showing” method.So a new path planning algorithm was proposed based on the clearance plane,then it was implemented into the domestic measurement software DirectDMIS,the problem that automatic path planning in teach-by-showing progress under specific measurement situation was solved without adding any operation and setting of the CMM software.Finally,by comparing the path planning results with PC-DMIS,the effectiveness and practicability of the algorithm were verified.