This study investigates the combustion performance of gas-oxygen and gas-methane pintle injectors, which discusses the influence of pintle injector structure design parameters and thrust chamber combustion design parameters on the combustion performance. Theoretical analysis is carried out by numerical simulation and other methods. The simulation results show that the oxidizer central pintle injector has a higher combustion performance. A larger angle of the pintle head and a smaller distance of the intermediate sleeve have a higher combustion performance. A smaller pintle head radius can significantly play a role in cooling the pintle head, but there is a certain loss of combustion performance. When the speed ratio is about 1.1, the combustion performance is higher, and the temperature of the pintle head is lower. When the mixing ratio of oxygen and methane is around 3, the combustion performance is higher.