The invention discloses a ground signal receiving and sending device, an underground signal receiving and sending device and a data transmission system, wherein the ground signal receiving and sending device is arranged at the ground end of a drill well, and comprises a ground antenna module, a receiving and sending switching module, a first signal receiving circuit, a first signal sending circuit and a first data processing module; the ground antenna module is used for converting received electromagnetic signals from the underground position into electromagnetic signals, converting the electromagnetic signals carrying ground information into electromagnetic signals and sending the electromagnetic signals to the underground position; the receiving and sending switching module is connected with the ground antenna module; the first signal receiving circuit and the first signal sending module are respectively connected with the receiving and sending switching module; the first data processing module is connected with the first signal receiving circuit and the first signal sending circuit; the receiving and sending switching module isolates the first signal receiving circuit and the first signal sending circuit. The system has the advantages that the data two-way transmission between ground equipment and underground equipment can be realized; the pump starting or stopping is not needed; the drilling time is not delayed; the misoperation cannot be easily generated.