An inside-and-outside dual-injection type pre-stressed anchor cable structure for a roadway floor penetrates through a grouting reinforcement area, a grouting stop layer, a floor layer and a rubble layer. A hole is drilled in the structure, an anchor cable is inserted in the hole, and a lock and an outer casing pipe are installed outside the anchor cable. An inner grouting pipe and an outer grouting pipe are installed inside the outer casing pipe. The interior of the lower end of the outer casing pipe is fixedly sealed by Malisan materials, the interior of the upper end of the outer casing pipe is fixed through cotton yarn in a packing mode, and the upper end of the outer casing pipe is flush with the floor layer. The upper end of the anchor cable, the lock, the upper end of the outer grouting pipe and the upper end of the inner grouting pipe are all exposed out of the floor layer, are horizontally laid on the surface of the floor layer through three-hole flat pallet sets, are fixed to the outside of the outer casing pipe and the outside of the anchor cable and are fixed through quick-hardening cement and cement paste liquid in a filling and sealing mode respectively. Shallow-hole grouting pipes are downwards inserted in the grouting layer and the floor layer. The structure not only can be used for floor heave treatment and enables the anchor cable to have high pre-stressed force within a long range, but also can improve the deformation resistance and fracture resistance of bottom plate surrounding rock and prevent the anchor cable from being corroded, wherein deformation and fracture are caused by influences of horizontal pressure and dynamic pressure.