Roadway floor heave protection device

The utility model provides a roadway floor heave protection device, which relates to the field of coal mining and comprises a roadway, a concrete layer is arranged at the bottom end of the inner side of the roadway, a plurality of first connecting plates and a plurality of second connecting plates are arranged at the top end of the concrete layer, inserting rods are arranged on two sides of each first connecting plate, and connecting blocks are arranged on two sides of each second connecting plate. According to the protective device, the inserting rods are connected to the inner sides of the connecting blocks in an inserted mode, so that a plurality of mutually-connected square frames are formed between the first connecting plates and the second connecting plates, and the square frames and the concrete layer protect a roadway bottom plate; when the bottom heaving phenomenon happens to the roadway bottom plate, only part of the square frame composed of the first connecting plate and the second connecting plate