Through the rapid freeze thaw test and micro pore structure test, the relative dynamic elastic modulus, freeze thaw damage degree and strength of basalt fiber reinforced concrete(BFRC) after freezing and thawing cycles in water and NaCl solution with concentration of 35%(by mass) were studied. The relationships of the pore structure parameters(air content, specific surface area, spacing factor, average chord length) with the compressive strength, flexural strength and freeze thaw damage degree of BFRC were investigated. Finally, the influences of pore structure parameters on compressive strength, flexural strength and freeze thaw damage degree were studied by means of grey entropy analysis. The results show that the strength of BFRC decreases with the increase of air content, spacing factor and average chord length, and the freeze thaw damage degree of BFRC increases with the increase of the above three pore structure parameters. The strength of BFRC increases with the increase of specific surface area, and the freeze thaw damage degree of BFRC decreases with the increase of specific surface area. The most important influential factor on the compressive and flexural strength of BFRC is specific surface area, and the main influencing factors of the freeze thaw damage degree of BFRC are spacing factor and average chord length with different freez thaw cycles and different basalt fiber contents.