Abstract: Under the condition of slicing recovering in giant thick coal seams, the intense repeated mining-induced disturbance causes the roof to be extremely fragmented. This leads to water gushing from the upper layer and the shallow working face, which then seeps downward and accumulates in the lower layer and the deep working face. The mechanism of this leakage process is complex and does not follow the traditional seepage theory. Instead, it exhibits distinct characteristics of fracture flow or pipe flow, making it difficult to accurately predict the water inflow at the working face under such conditions. Taking the 1412 working face of Barapukuria Coal Mine in Bangladesh as an example, the deficiencies and inapplicability of the traditional water inflow prediction method based on seepage theory under such complex conditions were systematically analyzed; subsequently, a new method for predicting water inflow based on the quantitative estimation of leakage volume through the spatial position relationship of the working face, the mining sequence, and the water attenuation degree of adjacent working faces was proposed; at the same time, a groundwater numerical model was constructed based on the ground water math simulation (GMS) software, and the water inflow during the mining of the 1412 working face was predicted using the numerical simulation method, and the evolution law of the groundwater flow field was revealed. The research results show that the numerical simulation based on the GMS Drain module has a fitting degree of 96% for the water inflow volume, with a relative error of 4%. The water volume reduction factor range established based on the leakage volume estimation method is 57% to 80%, and the fitting degree of the predicted water inflow volume is 97.8%, with a relative error of only 2.2%. Both the leakage volume estimation method and the numerical simulation method can accurately predict the water inflow volume under this complex working condition, providing an effective reference for the prediction of water inflow volume slicing recovering in similar conditions of slicing recovering in giant thick coal seams with strong disturbance or multiple coal seams superimposed mining.