The invention relates to a high-pressure-resistant high-temperature-resistant underground electronic tag, which consists of a high-pressure-resistant high-temperature-resistant shell (1), an integrated circuit (2), a circuit board (3), a receiving-transmitting coil (4) and a magnetic bar (5). The shell (1) is made of polysulfone, polyimide or high-strength zirconia ceramics, the integrated circuit (2) is connected with the circuit board (3) through high-temperature weld tin, the circuit board (3) is made of high-temperature-resistant epoxy substrate with thickness of 0.5mm, the receiving-transmitting coil (4) is formed by closely winding a lacquered wire onto the magnetic bar, and epoxy resin structural glue (6) is filled in the residual space of the high-pressure-resistant high-temperature-resistant shell (1) and the assemblies. The high-pressure-resistant high-temperature-resistant underground electronic tag is applicable to the underground process control of an oil production well, a gas production well and a water injection well in the development of the oilfield. The high-pressure-resistant high-temperature-resistant underground electronic tag has advantages of simplicity in construction, low operation cost, high pressure resistance and high temperature resistance, and is an advanced, reliable and accurate signal transmission method.