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With the shortage of fossil energy and environmental pollution becoming more and more serious, it is urgent to study the energy saving and emission reduction technology of construction machinery with large quantity and high energy consumption. In common construction machinery, such as excavators, cranes and hoists, there are large inertia hydraulic swing systems with frequently start and brake operations. During the braking of large inertia hydraulic swing system, the braking kinetic energy is converted into heat energy through the throttling effect of the valve port, resulting in a large amount of energy loss. If the braking kinetic energy of the swing system can be recycled and reused, it can not only reduce the energy consumption of the system and the cost of construction machinery, but also save energy and protect the environment. Therefore, an electrical and hydraulic hybrid drive large inertia swing system was proposed. In the system, as the main power source, the permanent magnet synchronous motor was used to control the movement of the swing system. The hydraulic motor, powered by the accumulator, was used as an auxiliary power source to provide torque compensation for the acceleration of the motor start-up, and the accumulator efficiently recovered the braking kinetic energy for reuse. In the research, a multidisciplinary joint simulation system model was established. Based on the principle of reasonable supply control of main and auxiliary power sources, a full-cycle condition recognition speed control strategy was designed. An electro-hydraulic hybrid drive swing test platform was built to analyze the characteristics and energy efficiency of the swing system. The results showed that the energy recovery efficiency of swing braking was 40.5%~65.9% with the change of rotational speed and rotational inertia. Compared with the pure motor drive system, the electrohydraulic hybrid drive system had a faster start-up acceleration of 1.2s, which can achieve a braking kinetic energy recovery efficiency of 63.5%, reduce system energy consumption by 40.8%, and make the swing system run more smoothly.