Taking a multi-robot production line as the research object, a multi-robot flexible manufacturing production line is established by RobotStudio. The layout of the production line is designed. According to the operation mode of the production line, the signal connection and robot program between the multi-robot and the equipment are studied. The logical relationship between the signals between the systems is established to monitor the collision between the robot and the equipment in real time. Meanwhile, the operation performance parameters of the robot are analyzed The working range of the robot and the position of the wrist joint are analyzed, and the simulation operation and analysis optimization of the multi-robot production line combining die casting, machining, welding and detection are realized. The simulation results show that the production line can be observed in real time, the working performance parameters of the robot can be analyzed and optimized intuitively, the optimal solution of the energy consumption and working time of the robot can be found, and the working range and the position of the wrist joint singular point of the robot can be observed at the same time. The research can provide reference for the establishment and optimization of multi-robot production line.