Coal mine goaf land subsidence detection device and detection method

The invention discloses a coal mine goaf land subsidence detection device and method, and the device comprises a support, a connecting rod is erected at the center of the support, the connecting rod extends towards the lower part of the support, and the outer wall of the part, below the support, of the connecting rod is slidably sleeved with a plurality of detection shells. A resistance block capable of being embedded into the stratum is distributed outside each detection shell, the support further comprises a data processing device, the detection shells are fixedly connected with the connecting rod at the joint part of the connecting rod through a loop bar, the loop bar and the detection shells form a cavity, a spring is arranged outside the loop bar in a sleeving mode, and the spring is connected with the data processing device in a sleeving mode. The two ends of the spring are fixedly connected with the sleeve rod and the detection shell respectively, a pressure sensor is slidably arranged in the sleeve ro