The utility model provides a secondary vacuum pug mill for pottery clay. The secondary vacuum pug mill comprises a motor controller, a motor, a speed reducer and a pug mill device, the motor controller is connected with the motor through a circuit, the motor is a direct-drive motor in transmission connection with the speed reducer, and an output shaft of the speed reducer is directly connected with a spindle of the pug mill device through a coupling. Compared with the prior art, the secondary vacuum pug mill has the advantages that transmission intermediate links are fewer, electricity is saved, and the service life is long.