According to the traditional inspection method for straight bevel gear’s tooth shape error based on the contact moulage exists defects of difficult quantitative description of geometric errors and poor trace ability vector-valued, a kind of tooth shape error measurement and evaluation method of straight bevel gear based on electrical generating is presented. Firstly, the theory tooth shape of straight bevel gear and mathematical model of tooth shape error measurement is established, then sensor in space scanning straight bevel gear’s tooth shape and forming theory curve on the gear measurement center is controlled based on the closed-loop AC servo control system, tooth shape error of straight bevel gear is measured and evaluated based on the sensor readings in the process of continuous scanning. Experiment results show that, this method can realize the automatic measurement and evaluation of straight bevel gear’s tooth shape error in existing CNC gear measurement center, and has signifi cant advantage of the measurement effi ciency, high degree of automation, and good vector-valued traceability.