Due to the large moment of inertia of the rotary platform on the excavator, the braking starts at high frequency, a large amount of braking kinetic energy is converted into heat energy at the valve port of the control valve and wasted. A double-motor active and passive combined drive excavator rotary system was put forward. The valve port independent control was adopted in active system, and pump-valve combination and pressure-flow matching control strategy were used to restrain throttling and overflow loss. The advantages of valve port independent control with multiple degrees of freedom were used to solve the impact and reversal problems in braking stage. The hydraulic motor-accumulator combination in passive system was adopted to recycle the braking kinetic energy of the rotary platform. During no-load braking, oil was replenished to the accumulator by booster cylinder. The electro-hydraulic co-simulation model of rotary system was established, and the operation and energy characteristics were analyzed. The results show that the energy recovery rate of the accumulator is 79% and 72% in full-load and no-load braking stages, respectively. The problem of insufficient oil recovery of the accumulator is solved by the booster cylinder, and the energy consumption of the accumulator is reduced by 54.3% compared with that of the traditional rotary system.