Abstract: The jet noise of launch vehicle engine is the main factor causing the random vibration environment of rocket cabin. For the solid-liquid strap-on rocket, the combined bundling effect of jet noise of multiple solid booster engines and core liquid engine will make the high-frequency random vibration of the cabin more severe, especially for the tail cabin of the solid booster engine near the engine nozzle. Focusing on the high-frequency random vibration environment of equipment in a sample-staged tail cabin and their support mounting surface of a solid-liquid strap-on rocket under noise excitation, this paper used the finite element analysis (FEA) method to investigate the optimization of the random vibration environment. The results show that the high-frequency random vibration response of the mounting surface can be significantly improved by increasing the thickness of the equipment support frame. Based on the obtained result, the support of a unit equipment was redesigned and tested. The maximum deviation between the tested results and the simulation predicted results all meet the ±3 dB deviation range generally required in engineering. The feasibility of the environmental optimization and prediction analysis methods is verified. The proposed research may provide a reference for the optimization and prediction of high-frequency random vibration for the follow-up carrying cabin under noise excitation.