In order to solve the problem of on-site cutting of reinforced concrete pole of overhead contact system,asplit type cutting saw structure was proposed, and the cutting saw and its hydraulic system were designed. The influence of key parameters of the accumulator on the pressure of the cutting circuit was analyzed. The key parameters of the accumulator were optimized by NLPQL method. The results show that the accumulator precharge pressure has obvious influence on the hydraulic impact of the cutting circuit, while other parameters have no obvious influence; the optimized accumulator can greatly reduce the peak pressure of the cutting circuit, making the circuit pressure nearly stable, sothe stability of the system is improve.