The invention belongs to the technical field of wireless monitoring, and relates to an underground condition wireless monitoring device. The major structure of the underground condition wireless monitoring device comprises two functional parts, namely monitoring units and a data processing terminal, wherein the monitoring units are in wireless communication with the data processing terminal; and each monitoring unit comprises an external thread, a lower protective sleeve, a middle short section, a first through hole, a second through hole, an upper protective sleeve, a centralizer, an internal thread, a sensor module, a circuit module, a battery module, a sealing cover, a lower instrument cylinder, an upper instrument cylinder, a groove, and a transmitting transducer and auxiliary circuit module which are interacted. The underground condition wireless monitoring device is applied to downhole condition monitoring during oil and natural gas drilling and production, downhole condition monitoring during coal mine drilling and production, pile hole monitoring during foundation construction of construction engineering piles, and underground condition monitoring during other long-distance operations utilizing drill stems or pipe columns; and the structure of the underground condition wireless monitoring device is simple, the principle is scientific and reasonable, the operability is strong, the use is environmentally friendly, the universality is strong, and the popularization and the use are easy.