Abstract: The Jurassic coalfield in northern Shaanxi has the characteristics of shallow burial, large thickness and multiple layers. With the high-intensity mining in the past two decades, a large number of mines have begun to enter the lower coal seam mining, and the mining depth has gradually increased. The overlying goaf has an increasing impact on the lower coal seam mining, especially in the lower coal mining roadway. The influence of the upper coal goaf is more significant, and there are coal pillar spalling, roadway floor heave, mesh damage and other mine pressure behavior. Taking the 15211 working face of Zhangjiamao as an example, the above problems exist in the return air roadway. In order to ensure the safe mining, on the basis of fully considering the factors such as the thickness of overburden rock, the lithology of overburden rock, the superimposed stress of overlying goaf and the width of coal pillar, the water pressure pre-splitting technology is used to weaken the strata in the range of 18.0 m near the goaf side of the return air roadway. After the implementation of high-pressure water pre-splitting technology, the construction section and the non-construction section are compared: during the non-weighting period, the stress is reduced by 42.4 %;during the periodic weighting, the stress is reduced by 40.1 %, and the deformation of the roadway is significantly reduced, thus the expected pressure relief target is achieved. The safe mining under the superimposed stress of multi-seam goaf in 15211 working face is realized.