To effectively solve the problem of an angle measurement error brought during measurement of an encoder when crossing a zero point, the invention provides a zero-point-crossing processing method. The method includes the steps of: (1) obtaining an initial value of an encoder; (2) determining the zero-point-crossing type; and (3) performing zero-point-crossing processing according to the zero-point-crossing type. The zero-point-crossing processing method of the encoder is realized by adoption of a method of comparing a collected value with the initial value of the encoder, and can effectively solves the problem that an angle collection error is caused when the encoder crosses the zero point.