A new 5Joint mechanical arm was designed which control program could be obtained based on kinematic theory equation. A friendly interface platform was designed which contributed to remote control. The mechanical arm was structured with four lever 5 joints of a serial mechanism, with its longest stretch distance up to 125 cm. At first, equation of motion of the mechanical arm was established based on inverse kinematics theory. The tip position of the gripper could be controlled by using servo motor to adjust the angle between relative links. The whole system was programmed by VB programming language, when the operator clicked the desired position on the screen, the program would compute the corresponding servo angles automatically through inverse kinematics theory, and then conveyed the instructions of angle variation to the servo motor which adjusted the servo angle simultaneously, so that end gripper of the mechanical arm could reach the position that the operator specified. The mechanical arm is mainly used for rescue robotics, and therefore does not require high precision operation, comparing experimental results with theoretical ones, it can be clearly seen that operating precision of control system within the scope of the permit.