Concrete surface crack cracking extension monitoring device

The utility model discloses a concrete surface crack cracking and expansion monitoring device in the technical field of concrete, the concrete surface crack cracking and expansion monitoring device comprises a concrete body and a detection pipe, two connecting grooves are formed in the side end of the concrete body, connecting assemblies are arranged between the two connecting grooves and the detection pipe, and each connecting assembly comprises an inner threaded cylinder and a fixing block; the inner threaded cylinder is fixedly arranged in an inner cavity of the connecting groove, the fixing block is fixedly arranged on the outer side of the end, close to the concrete body, of the detection pipe, and a bolt is arranged at the side end of the fixing block in a penetrating mode and is in threaded connection with the inner cavity of the inner threaded cylinder. A sealing mechanism is arranged between the detection pipe and the side end of the concrete body, a pressure applying mechanism is arranged in an inne