The invention discloses an unmanned aerial vehicle (UAV) and a method for monitoring coalfield fire area distribution and combustion situation. The UAV is composed of a wireless communication module, a control system, a data storage module, a power supply, an inertial navigation system, a space positioning module and a data monitoring module. The main operation method comprises: the control system of the UAV receives an instruction of a ground host to start flight, the inertial navigation system, the space positioning module and the data monitoring module acquire and synchronize exterior orientation attitude information in real time, and the ground host simulates and fits coalfield fire area geomorphic characteristics by using orientation information and geomorphic image information acquired by the UAV, and integrates infrared thermal imaging information, hybrid index gas proportion indexes (e.g., CO/CO2) and atmospheric temperature and humidity to predict coalfield fire area surface temperature distribution characteristic and corresponding fire combustion situation. The UAV and the method can quickly and safely simulate the geomorphic characteristics and surface temperature field distribution of a large-range coalfield fire area and predict the fire combustion situation.