The combustion characteristics of single-element and multi-elements splash platelet injector were studied by experimental methods, the heat load of injector faceplate under different working conditions were investigated, and the effects of different mixing ratios and different structural parameters on combustion chamber pressure and combustion efficiency were obtained. Results show that the mixing ratio of the multi-elements injector has little effect on the chamber pressure, but has a greater effect on combustion efficiency. For single-element injectors, the combustion efficiency improves with the increase of the mixing ratio. Under the same conditions, increasing the expanding angle and the length of the trapezoidal orifice is beneficial to improve the combustion efficiency, but will cause the increase of the thermal load of injector faceplate. The injector faceplate of each injectors has different degrees of deformation or failure. These results are of significance for guiding the design of the platelet injector and screening the structure of the injector.