Air supply pressure and oil content are the main effecting factors on lubrication performance of the bush in experiment optimization of oilair lubrication system characteristics.The temperature change on the bush and the chamber and the friction coefficient were often used as indicators to evaluate the lubrication characteristics of the bush.The multiquadratic regression models to predict the lubrication effects of the bush were established by means of center composite design method,and effectiveness of the predicting model was verified.The response surface methodology was used to produce response surfaces and contours of the relation between air supply pressure and oil content with the temperature rising of bush and chamber and the friction coefficient.The conclusion that the air pressure and oil content has remarkable interactive effect on the lubrication performance of the bush was drawn.The best parameters of the lubrication experiments were obtained by using numerical analysis software DesignExpert to solve the extremum of the predicated models.