Runoff yield from revegetated grasslands with different coverage of biocrust was measured by simulating rainfall in the study. Meanwhile, the relationship between biocrust coverage and CN value of SCS-CN model was analyzed. The results showed that: (1) Under a 90 mm/h rainfall intensity, the initial runoff yield time decreased against the increase of biocrust coverage, and the initial runoff time with low biocrust coverage (0~20%) was 1.64 and 2.46 times of that with medium biocrust coverage (40%~60%) and high biocrust coverage (80%~100%), respectively. (2) In the first 15 minutes of rainfall, biocrusts with high coverage promoted runoff yield compared with medium and low biocrust coverage. After 15 minutes, high biocrust coverage inhibited runoff yield compared with medium and low biocrust coverage. After 45 minutes of rainfall, runoff coefficient of each treatment tended to be stable. (3) There was a significant negative correlation between biocrust coverage and runoff depth, and runoff depth decreased in the form of logarithmic function with the increase of biocrust coverage (y=-13.87ln x+73.515,R²=0.761 4). (4) By adjusting CN value, SCS-CN model could be suitable for runoff estimation from biocrustal slope, and there was a significant negative correlation between biocrust coverage and CN value, the relational expression is that CN=-0.2672×C_BSC+79.0166,R²=0.680 0. In which, C_BSC was the percentage coverage of biocrust. In this study, the influence of biocrust on the parameters of runoff model was revealed, which was of great significance to the establishment of hydrological model considering biological crust.