Conventional design method of downhole tractor is based on cementing casing, which is only suitable for smooth hole. For the open hole well, the conventional downhole tractor has poor adaptability and even can not work normally. Based on this, a support adjustment mechanism with double push rod-double spring was proposed to improve the obstacle surmounting performance of wheel tractor and expand its application range. By using the software of motion simulation, the kinematic simulation numerical models of conventional support adjustment mecha-nism and support adjustment mechanism with double push rod-double spring were established. The in-fluence of different obstacle forms on the obstacle surmounting performance of the two kinds of sup-port adjustment mechanisms was analyzed. The results show that the support adjustment mechanism with double push rod-double spring has better obstacle surmounting performance than the single push rod support mechanism. The double push rod and double spring support adjustment mecha-nism can effectively promote the further research and application of the tractor in the open hole well.