The utility model discloses a novel remaining pressure power generation system for a natural gas high-pressure pipe network. The system comprises a pretreatment device, a turbo expander, a gearbox, an electric generator, a filter I, a current transformer, a filter II and an electric quantity inductor, wherein the pretreatment device, the turbo expander, the gearbox, the electric generator, the filter I, the current transformer, the filter II and the electric quantity inductor are sequentially connected. The gas outlet end of the pretreatment device is communicated with the gas inlet end of the turbo expander and the gas outlet end of the turbo expander is communicated with the gas inlet end of a heat exchanger. The work processes of the pretreatment device, the turbo expander, the gearbox, the filter I, the current transformer, the filter II and the electric quantity inductor are controlled by an automatic controller. The urban natural gas high-pressure pipe network contains large pressure energy, the novel natural gas remaining pressure power generation system which is novel, reliable and high in cost performance ratio is designed according to the condition of natural gas pipe networks in China, and the purpose of stable power generation under the condition of large natural gas flow and pressure fluctuation is thoroughly achieved.