This study selected the typical steppe of Inner Mongolia surface area analyzed the applicability of PDSI in semi-arid and semi-humid steppe surface. From the correlation results between the PDSI results of each single point and the regional average PDSI, as well as the comparative analysis between the PDSI and the precipitation anomaly percentage, the standardized precipitation evapotranspiration index, the normalized vegetation index and the actual drought records, it can be seen that the PDSI results and the comparative analysis results of other drought indicators have good correspondence in terms of the consistency of time trend and the consistency of spatial distribution, indicating that PDSI in the typical grassland surface area has good applicability, can well reflect the drought conditions under such the surface condition. And PDSI has time lag when indicating frequent alternate of droughts and floods. The research results can provide reference for the fine application of PDSI in similar areas and the remaining surface condition under analysis.