In view of the influence of groundwater on the safety and stability of rock slope, taking the left cutting slope with excavation depth of about 200 m of zhongyuntai mountain, Lianyungang as the research object, the groundwater distribution on the slope was studied and the seepage interception effect of fine aggregate concrete spray layer on the excavated slope was evaluated through calculation and analysis of groundwater monitoring data. The results show that the groundwater supply source of the slope is rainfall infiltration and the abandoned quarry at the south end of the slope is the main discharge area. There is a strong hydraulic connection between the four platforms where the osmometer is embedded. The aging damage of the fine aggregate concrete spraying layer in the area with high seepage flow is higher than that in other areas, but on the whole, the seepage interception effect of the fine aggregate concrete spraying layer is better.