Abstract: According to the present status of poor vibration isolation performances of the suspension system in mine flame proof vehicle and the poor sitting comfor tbility, a mixed air suspension device suitable applied to the mine flame proof vehicle was provided.The paper stated the calculation formula and the selection method of the air spring.In order to meet the combined application and coordinated actions of the air spring and the height control valve, a control system of the mixed air suspe nsion frame was designed.The suspension device was applied to the WC6R (B) mine flame proof command car.The industrial experiments and actual applications show ed that the available frequency of the suspension frame could be suitably varied according to the requirements.With the advantages of the varied rigidity feature, adjust able height, good vibration isolation performance, light weight and others, the sitting comfortability was improved.