Abstract: [Objectives] The shock environment characteristics of a large floating shock platform (LFSP) under the action of an underwater blast load were analyzed, [Methods] based on the acoustic solidification method for the numerical simulation of LFSP underwater blast, verify the validity of the calculation method by comparing the experimental and simulation data ,the shock environment of the LFSP was studied in terms of its longitudinal profile distribution and the effect of the change of the lateral distance of blast source on the shock environment. [Results] Floating platform in the bottom of the face of the blast surface, back blast surface, the middle of the longitudinal surface shock environment along the longitudinal distribution pattern was basically the same, with the shock environment on the first and last sides was small and the middle was large. The shock environment of the back and forth side of the floating platform differs, the velocity value of the spectrum of the back side of the explosion was greater than that of the front side, the main reason was that the back blast surface measurement points within the bottom of the local mode were excited, shock spectral lines appear spikes, the displacement value of the spectrum of the front side was greater than that of the back side, the main reason was that the burst distance was smaller, shock response was stronger. The analysis of explosion source distances on the overall shock environment of the inner bottom, and the fitting of the floating platform shock environment prediction formula. [Conclusions] The results obtained can provide a reference for the floating platform assessment test.