Through non-steady-state heat flow method and the PCK experimental device, the basic thermal physical quantities of fiber-reinforced composites were determined, the temperature on the heat transfer and wet migration characteristics was investigated, and the simplified equations between thermal conductivity, moisture diffusion coefficient and temperature were obtained. Considering the non-uniform of fiber-reinforced composites, one-dimensional humidity and heat transfer numerical analysis model of fiber-reinforced composites in fire condition were established. Numerical simulations of the material from crack initiation to thorough extension were conducted. Contrast material specimen at different times, the temperature distribution, pressure distribution and the crack depth, the peak intensity, the crack and burst characteristics were studied. Fiber-reinforced composites with different moisture contents after heating were tested to verify the performance of the thermal explosion and numerical analysis of indicators. The results have shown that the test and numerical analysis are basically the same and the pressure peak grows with the migration coefficient, making the materials durable.