Abstract: Taking Zhanghe reservoir in Hubei province as an example, the runoff simulations of Xin'anjiang model and SCS model under the condition of minute precipitation were analyzed based on the precipitation and discharge data from 2008 to 2017. At the same time, combining with a event at Zhanghe reservoir from June 27 to 29 in 2020, the simulation characteristics of the two models in the extreme flood event in different basins were compared and analyzed. The result show that:(1) The efficiency coefficient of Xin'anjiang model was 10%-20% higher than that of SCS model, and the relative errors in flood peak and the peak time difference are comparable. But SCS model can be used for runoff simulation in areas without hydrological data. (2) In the simulation of the Zhanghe reservoir historical case, the time resolution threshold existed in the efficiency coefficient of Xin'anjiang model and SCS model, and the resolution threshold of Xin'anjiang model was smaller than that of SCS model. When the resolution was about 15 min, the relative error of flood peak and the peak time difference of the two models can reach the minimum value. (3) In the simulation of the flood in 2020, the two models had the optimal time resolution threshold that is 10 min both in efficiency coefficient and relative error of flood peak.