In the centrifuge of the multi-parameter combined environmental testing device, the three-phase induction motor could not be started directly at the frequency of 50Hz due to the large moment of inertia of the centrifuge rotor. Therefore, large torque output of the three-phase induction motor was required at low frequencies. And the specimen needed stepless rotational speed adjustment (40-130r/min). A set of frequency control system was developed based on vector control with PG, inverter and LabVIEW to solve these problems. The principle of the centrifuge was present. The principles of vector control with PG of three-phase induction motor were analyzed. Based on the mechanical characteristic of three-phase induction motor, vector control with PG was employed in the system. The system control software based on LabVIEW was presented, which realized stepless speed adjustment of the centrifuge on a computer. Experimental results show that the developed system could realize the stepless regulation of the specimen’s centrifugal acceleration.