Abstract: While the industrial robotic manipulator is a kind of multi-input and multi-output human-like operation and highly autonomous control system. It is widely used in medical care, home service, industrial manufacturing and other fields. With the integration of cyber-physical system networks and the Internet in recent years, the control commands of the industrial robotic arm control system can be totally exposed to the Internet. Under these circumstances, the chances of successful attacks by attackers to systems are increasing year by year. Compared to the security of traditional cyber physical system, the security of manipulator control system is a very challenging problem. In this paper, a covert attack method of 7 degrees of freedom (7-DOF) manipulator control system was proposed. Firstly, based on the inverse kinematics equation of the manipulator, the motion planning and modeling of 7-DOF manipulator, which communicated by EtherCAT, was carried out. Secondly, according to the research and analysis of particle swarm optimization method, a 7-DOF manipulator system PID parameter identification algorithm based on chaotic theory for multi- swarm particle swarm optimization was proposed. Parameter identification mainly identified the PID parameters of each joint. The principle and derivation process of the algorithm were described in detail. Finally, the experimental platform of manipulator control system was built and the identified parameters were used in combination with the covert attack principle to conduct the experiment. The proposed method was compared with other traditional attack methods, such as state machine attack and traditional sine attack. The results show that the covert attack model of the proposed 7-DOF manipulator can destroy the data integrity and accuracy of the manipulator system, and has a good concealment, which verifies the effectiveness and feasibility of the established attack model. The attack experiment platform constructed in this paper provides the physical basis for the attack and defense experiment of the manipulator, and it has certain reference significance for similar researchers.