In order to improve the performance of the automobile comfort, the dynamic characteristics and the vibration isolation characteristics of engine air spring hydraulic mount with variable stiffness and damping are studied. Firstly, the equivalent volume stiffness of the upper chamber, which is the key parameter affecting the dynamic characteristics of the engine air spring hydraulic mount, are studied by theoretical and experimental methods. Based on this equivalent value, the theoretical model of the air spring hydraulic mount is established, and the simulation and experimental study of the dynamic characteristics of the air spring hydraulic mount are carried out under the two conditions of air chamber opening and closing. Then, the test bench of the engine air spring hydraulic mount system is built, and the vibration isolation characteristics of the air spring hydraulic mount under various frequencies of the bench are studied. The results show that the proposed modeling method is accurate and feasible, and this method effectively improves the efficiency of modeling. By comparing the on and off working conditions of air chamber, the increase of dynamic stiffness is 78.5% and the increase of damping angle is 250%. The bench test shows that the vibration isolation rate of the mount increases obviously when the excitation frequency of the bench is less than 25 Hz, the mount adopts large stiffness and large damping, and when the excitation frequency is greater than or equal to 25 Hz, the mount adopts small stiffness and small damping. The amplitude of the increase reaches 10%~67% at different frequencies.