Abstract. The purpose of this paper is to ascertain the meshing point position of the cycloidal-pin wheel, which is the basis of studying the transmission performance of RV(Rotate Vector) reducer in robot. In terms of the general theoretical tooth profile equation of cycloid gear in RV reducer , the space meshing motion relationship of cycloidal-pin wheel is analyzed. Finally, the accurate meshing points positions of standard cycloidal-pin wheel and modified cycloidal-pin wheel at any angle under no load are obtained by means of tooth contact analysis(TCA). The results prove the meshing theories of cycloidal-pin wheel drive and provide the theoretical support for the actual meshing performance analysis of cycloidal-pin wheel planetary transmission.