The accurate prediction on the spatial distribution of water inflow and seepage characteristics in the cavern is one of the basic tasks to ensure the safety and economy during construction and operation of the underground water-sealed oil cavern. In order to study the seepage effect of randomly distributed fractures in the surrounding rock of underground water-sealed oil storage cavern on water inflow prediction and spatial distribution of seepage field, a seepage analysis method of fractured rock mass based on embedded fracture element (EFE) is proposed to analyze the three-dimensional seepage field in Zhanjiang water-sealed oil storage caverns. The reliability of the proposed method is validated by the measured data and calculated results, and then the water inflow of the this project during the operation period is predicted. The calculation results show that the EFE model can well simulate the influence of fractures on the local seepage field of fractured rock mass, and reflect the non-uniformity of spatial distribution of the seepage field and water inflow in caverns. The research results can provide references for the precise design of seepage control measurements for water-sealed caverns and the design of sewage treatment facilities during the operation period.