Based on HY-Z04 type scissors linkage seat, SK37-6 type diaphragm air spring being used as elastic element, the experimental system of scissors linkage seat air suspension with auxiliary chamber was established. The effect laws of orifice opening, mass on spring and actuator frequency on the vibration characteristics of seat were experimental studied. The results showed that, the natural frequency of seat suspension will decrease with the increase of orifice opening, and the damping caused by orifice will increase first, and then decrease. When the actuator frequency is low relatively, the effect of orifice opening on acceleration is very gentle, but when the actuator frequency tends to high, the acceleration root mean square value of seat will decrease with the increase of orifice opening, and the relation between orifice opening and acceleration root mean square value is nonlinear.