Abstract: Aiming at studying the effect of load-temperature coupling on the triaxial compressive permeability of concrete mixed with imitation steel fiber (ISF) and polyvinyl alcohol fiber (PVAF), research on the relationship between permeability evolution and stress state of ISF-PVAF hybrid fiber concrete was conducted. The triaxial compression permeability test under the condition of fixed confining pressure and seepage water pressure was carried out to obtain the stress deformation curves, peak strength and permeability at each stress point. Combined with SEM, the change mechanism of macro properties was revealed from the perspective of internal micro structure change. Results show that the coupling effect of load-temperature makes the porosity of hybrid fiber concrete decrease slightly at first and then increase significantly, the maximum increase reaches 80.48%, which is not conducive to the development of triaxial compressive permeability strength. While the behavior of initial permeability increasing is more affected by temperature, the initial permeability increases by 144.60% and 291.55% respectively at 200℃ and 300℃ compared with 100℃. According to the characteristics of stress deformation curve, the triaxial compressive permeability process is divided into four stage: Initial compaction stage, elastic stage, crack development stage and softening stage. The variation of stress state leads to the changes of micro cracks and residual fiber tunnels in hybrid fiber concrete, which directly affects the seepage path of pore water. As a result, the permeability in each stage exhibits different characteristics: Sharply decreasing, gently changing, rapidly rising and maximum increasing, respectively.