A method for conditional handover, a terminal device and a network device are provided. The method includes that: CHO configuration information is received, where the CHO configuration information includes measurement configuration information of a source cell; CHO processing is performed according to the CHO configuration information. In the solution provided in the application, since the CHO configuration information received by the terminal device includes the measurement configuration information of the source cell, the terminal device may perform CHO related measurement by using the measurement configuration information of the source cell, so as to reduce the number of measurement parameters maintained by the terminal device and reduce the complexity of CHO.