In order to solve the problems of kinematics coupling, a method was put forward based on kinematics. Kinematics coupling mechanism of 3-PTT series-parallel machine tool servo feed system was analyzed. Based on hooker and motion characteristics of series, parallel institutions pose decoupling method was used for analysis. The ADAMS and Matlab were used for simulation. The results showed that this analysis could reflect the kinematics coupling of 3-PTT CNC serial-parallel machine. It had high velocity and small coupling error. The research process could effectively solve the problem of series-parallel CNC machine tool servo feed system kinematics coupling.