The main type of rail transit equipment used in non-electrified railways is diesel multiple units (DMUs) powered by traditional fossil fuels, which suffers from low efficiency and high fuel consumption. To address this issue, a configuration scheme for a hybrid power pack for railway equipment was designed, and a mathematical model for the hybrid locomotive was established. The operational status of this configuration scheme under different modes was investigated, and an energy management strategy based on dynamic programming algorithm was proposed, with considering the operating conditions. Simulation results demonstrate that with this energy management strategy, the fuel economy of the hybrid powertrain locomotive is improved by over 32.11% compared to that of the pure fossil fuel locomotive.