The invention relates to an underground environment monitoring system and method based on a mooring unmanned aerial vehicle, and belongs to the field of underground environment monitoring. The underground environment monitoring system comprises a hand-held terminal and a PC in wireless connection with a flat intelligent remote controller, the PC and a power converter are connected with a wound rotor through cables, the wound rotor is inside provided with a driving motor and a tension sensor, and the wound rotor is connected with a mooring unmanned aerial vehicle flight monitoring platform through a cable. The underground environment monitoring method comprises starting an automatic pay-off and take-up device; starting an acquisition system of the mooring unmanned aerial vehicle flight monitoring platform; acquiring environmental parameters, image information and motion parameters, and returning the above to a ground monitor station; carrying out data processing and analysis; judging whether the parameters exceed the standard, giving a danger alarm until people evacuate, and making a return flight; and flying to sky over the parking apron and safely landing. According to the invention, the technical problem that a conventional underground environment monitoring system is low in automation degree, hard to repair, low in safety, and poor in system stability, information transmission is limited, and the working time is restricted by electric energy is solved.