In order to improve the comprehensive performance of permeable concrete，nano-silicon and polypropylene fiber were added to permeable concrete to study the performance of the composite modified permeable concrete.Firstly，the influence of single-doped nano-silicon on the performance of cement paste and permeable concrete was studied，and the content of nano-silicon and the optimal water-to-binder ratio were determined.On this basis，different proportions of polypropylene fiber were mixed，and the reasonable content of polypropylene fiber was determined.The results show that nano-silicon improves the porosity of permeable concrete and increases the optimal water-to-binder ratio.When the content of nano-silicon is 0.5%，and the water-to-binder ratio is 0.32，the compressive strength of permeable concrete is the highest.Based on this ratio，the maximum compressive strength can be obtained by adding 1.0 kg/m3 polypropylene fiber，and the compressive strength after 7 d and 28 d is increased by 29.9% and 42.2%，respectively.Adding 1.5 kg/m3 polypropylene fiber has the most significant effect in improving the frost resistance of permeable concrete.After 300 freeze-thaw cycles，the residual rate of compressive strength and flexural strength are 62% and 75%，respectively，which are far higher than 40% and 55% of single-doped nano-silicon.