In this paper, a cable-driven puncturing surgery robot named CPSR is proposed for soft needle. The cable-driven mechanism has lower mass, smaller dimension and smooth transmission. The motor driving the rotational joints is separated using cable which strengthen the dynamic performance of the robot. A decoupling mechanism based on movable pulley is also proposed to reduce the transmission error. Transmission error of cable-driven mechanism are also analysed to improve the control accuracy. The simulation of transmission error is completed to optimize the design parameters of cable-driven mechanism. In puncturing experiments, the feasibility of the CPSR driving the soft needle using cable-based mechanism is validated. Also the insertion error less than 0.7 mm and repeatability less than 2.5 mm are achieved. Finally the reasons limiting the accuracy and corresponding solutions are discussed. In the future research, the shape sensor will be fabricated using optic fiber and mounted on the slim needle which is helpful to complete automated operations.