A method of approximate tooth surface relief in use of standard cutting tool was proposed with the advantage of machine flexibility. The tooth surface equation was established according to different types of modified cutting tool

the relived tooth surface was solved and the meshing FEA model was established. According to the gear meshing simulation of the FEA method

the transmission performances of different relived tooth surfaces were compared

and the arc-edged cutting tool was chosen as the optimization target according to the result. The higher order cutting motion was introduced

and the optimization model of tooth surface approaching was established according to the optimization target. The transmission performances of optimal tooth surface and unrelieved tooth surface were compared. Results showed that the first-order vibration amplitude decreased approximately 16.6% when optimal tooth surface was meshed

and the gear transmission performance was effectively improved.