The fuel and working fluid system supplies the test bench with required fuels such as natural gas, hydrogen, gas mixtures, and diesel oil, as well as working fluids including nitrogen, oxygen, and carbon dioxide. Composed of multiple compressor units, high-pressure storage equipment, cryogenic equipment, and regulating devices, the system enables independent or flexible blended supply of CH₄, H₂, CO, CO₂, and N₂ within a maximum flow rate of 30,000 Nm³/h and a maximum supply pressure of 6 MPa. It satisfies the test bench's complex operating condition requirements for fuel and working fluids, as well as the multi-fuel test requirements for gas turbine engines up to 30 MW.