The upper substation of Dashucun Mine's No.3 mining areas is located at about 19 m of the bottom plate of No. 2 coal seam, at the intersection of 172102, 172103 and 172102 working faces, and the upper section is located at the lower part of the goaf area of 172102 working face, the middle section passing through the isolated coal column between the three working faces, and the lower section is located at the lower part of the goaf of 172103 working face, and the roadway was in the high stress concentration area, and the roadway floor was about 7 m thick muddy siltstone with developed joints. After a week of construction, the bottom plate bulged 600～700 mm. considering the long-term use of the roadway as the upper substation of the three mining areas, the rapid deformation of the roadway bottom plate can no longer meet the needs of use, and if the installation of electrical equipment, affected by the heave of the roadway, may cause damage to electrical equipment, resulting in safety accidents. After discussion, it was decided to dig out the soft layer of the roadway floor and replace it with concrete + U steel bottom beam + flexible anchor cable + steel skeleton + deep grouting of the floor as an integrated impact-resistant artificially strong false bottom to reinforce the roadway floor, which achieved the purpose of preventing roadway deformation.