The study on soil infiltration characteristics and model adaptability under vegetation restoration can provide scientific basis for watershed ecological management and benefit evaluation.Taking Zhifanggou small watershed of Yanhe River as the study area

the field single-loop infiltration method and numerical simulation method were used to study the variation characteristics of water infiltration below the surface layer and below 20 cm soil of robinia pseudoacacia forest land

caragana korshinskii shrub land

secondary grassland and farmland under different restoration years

and the adaptability of four common infiltration models in the region was evaluated.The results showed that:(1) The infiltration process of soil below the surface layer of different vegetation restoration areas were significantly different in the infiltration and leakage stages

and the maximum difference was more than 4 times.The infiltration process below 20 cm was significantly different in the penetration stage after the infiltration stability

and the maximum difference was more than 5 times.(2) Different vegetation types and restoration years had significant effect on soil infiltration characteristics

showing the law of forest land > grassland > farmland as a whole.With the increase of restoration years

the infiltration capacity of caragana korshinskii land and secondary grassland increased

while the infiltration capacity of robinia pseudoacacia forest land decreased.(3) Philip equation

Kostiakov equation

Horton equation and Jiang Dingsheng equation all had good applicability to the soil water infiltration process in the region.Philip equation had the strongest applicability

and the determination coefficient R2 could reach 0.931~0.985

the root mean square error RMSE was relatively minimum

which was in the range of 0.057~0.283

followed by Kostiakov equation

but Horton equation and Jiang Dingsheng equation had deviation in individual cases.In conclusion

vegetation restoration will significantly affect soil infiltration capacity and show different laws with the increase of restoration years.Among various infiltration models

Philip equation has the best applicability to the soil water infiltration process in this area.