The invention relates to a fixture for a rectifier module of an excitation generator; the fixture involves an exciter rotor hub, a generator spindle and the rectifier module and comprises supports andrectifier module mounting plates; the supports are arranged evenly between the exciter rotor hub and the generator spindle; one end of each support is fixedly connected with the inner wall of the exciter rotor hub, the other end of each support is fixedly connected with the generator spindle, one rectifier module mounting plate is arranged between every two adjacent supports, a rectifier module is mounted at the inner side of each rectifier module mounting plate, and the middle of each support matched with the outgoing wire end of the corresponding rectifier module is provided with a transverse connection plate. The rectifier modules are arranged in the exciter rotor hub, and the actual acceleration of the rectifier modules is decreased; in addition, outgoing wires of the rectifier modules are connected together through a circular wire, and the axial size of the generator is decreased. The invention also relates to the excitation generator comprising the fixture.