In order to study the influence of thermal deformation of the cycloid ball meshing pair on dynamic performance of the precision ball transmission, the thermal deformation of contact point of the cycloid ball meshing pair was analyzed by the Green function method, and the influence of system parameters on thermal deformation was analyzed. According to the angle deformation of the planetary disk caused by thermal deformation of meshing pair, the expression of the meshing stiffness coefficient was derived, the factors affecting variation of the meshing stiffness coefficient were analyzed. The finite element single tooth model of meshing pair was established, the finite element simulation of thermal deformation of meshing pair was analyzed by thermal structure coupling. The results show that the thermal deformation of the epicycloid groove is higher than that of the hypocycloid groove, the maximum thermal deformation occurs in the vicinity of 1/3 tooth height of the epicycloid groove, the thermal meshing stiffness coefficient is approximately sinusoidal in a small range, the parameters of system have great influence on the thermal deformation and the thermal meshing stiffness coefficient. This study provides a theoretical basis for the thermal dynamic analysis of precision ball transmission.