Based on the hydrostatic and hydraulic auxiliary braking system of tracked vehicle, the hydraulic pump/motor efficiency model according to hydraulic pump/motor performance analysis was set up. The optimal working line in which the hydraulic pump/motor worked at the highest efficiency level was obtained. An energy regenerative braking control strategy was proposed which could lead to the optimal matching of hydraulic coupler, hydraulic pump/motor. The simulation and test results showed that the hydraulic pump/motor could achieve efficient operation, and the energy regeneration efficiency of braking was improved obviously with the regenerative braking control strategy under the safe braking conditions.