In order to realize stable working of giant vehicular photo-electric trackers, a method of vibration isolation is proposed for a tracking frame in a photo-electric tracker,in which a air spring and an electromagnet actuator is used to isolate the vibration.The layout of electromagnet actuator is differential, so the force of electromagnet actuator and the control current are linear.Several kinds of control methods are analyzed,and the absolute velocity feedback control method is chosen to keep the vibration isolation capability in high frequency and avoid syntony in low frequency vibration.The results of MATLAB simulation and experiment indicate that the high frequency amplitudes of z-DOF ,θx -DOF and θy -DOF have been reduced from 5×10-5 m to 1.8×10-5 m, 2.2×10-5 m to 0.6×10-5 m and 2.0×10-5 m to 0.4×10-5 m, respectively,meanwhile the syntony can be avoided.These results show that this vibration isolation method by absolute velocity feedback control can evidently promote the vibration isolation capability.