In this paper, the gas-liquid two-phase double-cavity self-excited oscillating fuel nozzle is taken as the research object, and numerical simulation method is adopted to study the influence of different structural parameters and temperatures on the internal flow characteristics of fuel.The results show that the effects of different structural parameters and fuel temperature on internal flow characteristics are obviously different, and the internal flow characteristics (mass flow rate, the cavity number, flow rate and turbulent kinetic energy) will increase gradually with the increase of fuel temperature.