Abstract: In this paper, the molded FRP material was taken as the research object, the high temperature ablation environment of the material was simulated by the oxygen propane torch flame test. Drew up the experiment plan and then started the experiment to FRP. The influence of ablation distance on the stability of flow field was studied under different heat flux values. It was found that when the heat flux value was greater than 1.0 MW/m², the ablative distance had less influence on the fluctuation of heat flux value, and the stability of the flow field was better. The influence of ablation time on the ablative performance of FRP was explored, and the reasons for the change of the surface morphology of FRP were analyzed. It was found that with the prolongation of ablation time, the mass ablation rate decreased significantly, and the consistency between the linear ablation rate and the mass ablation rate was poor. This was because the layered expansion of the molded FRP during the shorter ablation time resulted in the smaller linear ablation rate, but the weak carbon layer structure would result in the decrease of the quality of the material obviously. So the mass ablation rate was high. With the increase of ablation time from 60 seconds to 120 seconds, the layered accumulation of materials lead to the increase of material strength. The enhancement of erosion resistance decreased the mass ablation rate. Within the acceptable range of materials, the longer ablation time can accurately reflect the linear ablation rate of the material.

Key words: heat flux, stability of flow field, ablation time, liner ablation rate, mass ablation rate