To study the frost resistance of basalt fiber-slag powder-fly ash concrete （BSFC）， uniaxial compressive strength test， split tensile test， ultrasonic testing test and pore structure characterization test were carried out. The change rules of mass loss rate， relative wave velocity， relative compressive strength， relative splitting tensile strength and mesostructure characteristics of BSFC before and after freeze-thaw cycle were analyzed. The damage development was evaluated by multi-index of BSFC based on damage mechanical theory. The fractal dimension of distribution of air-void structure of the BSFC was calculated using the fractal theory. The contribution rate formula of basalt fiber under different number of freeze-thaw cycle was obtained by fitting the experimental data. Finally， the freeze-thaw damage model was established based on multiple factors such as fractal dimension and basalt fiber contribution. The results show that with the increase of the number of freeze-thaw cycle， the mass loss rate increases， but the P-wave velocity， compressive strength， and splitting tensile strength decrease； the air-void structure deteriorates and the number of harmful voids increases， and the fractal dimension of the pore structure distribution decreases. Under the same number of freeze-thaw cycle， compared with other fiber dosage， BSFC mixed with basalt fiber of 0.18% has the best frost resistance. The regression effect of freeze-thaw damage and fractal dimension of air-void structure and basalt fiber contribution rate is significant， which can predict the damage deterioration of BSFC after freeze-thaw cycles.