In this study, the physical and mathematical model of the hydraulic calculation of high-pressure gas pipelines in automobile gas-filling compressor stations was analyzed. The characteristics of variations in gas parameters within gas-filling compressor stations and pressurized gas pipelines during the process of refueling vehicles with natural gas were investigated. In improving the physical and mathematical model of hydraulic calculations, the local resistance coefficients arising from pipeline contraction and expansion were examined while considering the compressor compression ratio. Based on the results of physical and mathematical modeling, the local resistance coefficient for sudden expansion in the network pipelines of an automobile gas-filling compressor station was refined, and its comparative assessment was substantiated through experimental tests and theoretical calculations. A technology for the reuse of exhaust gas was proposed, taking into account changes in gas density, temperature, velocity, and pressure at the outlet of the compressor unit during the reuse process. Using Borda’s theorem, and considering variations in gas density, temperature, velocity, and pressure at the inlet and outlet of the compressor unit, graphical dependencies describing exhaust gas reuse were developed. Based on the physical and mathematical model of hydraulic calculations for high-pressure gas pipelines, a refined model for hydraulic calculation of gas flow in high-pressure pipelines was developed, incorporating the compression ratio and the local resistance coefficients associated with pipeline contraction and expansion.