The invention discloses a 
combustion detection 
system and a 
combustion detection method thereof. The 
combustion detection 
system disclosed by the invention comprises a transmitting terminal fixing device, a rotating table I, a transmitting device, a 
laser switching device, an 
optical path calibration device, a receiving terminal fixing device, a rotating table II, an 
optical filter, a receiving device and a photoelectric 
detector; the rotating table I and the rotating table II are respectively fixed on the transmitting terminal fixing device and the receiving terminal fixing device; the transmitting device is fixedly arranged on the rotating table I; the 
optical path calibration device is detachably arranged on the transmitting terminal fixing device; the 
laser switching device is connected with the transmitting device by optical fibers; the 
optical filter and the receiving device are coaxially fixed on the rotating table II; the receiving device is connected with the photoelectric 
detector by optical fibers; when an 
optical path is calibrated, the transmitting device transmits indicating light, the indicating light passes through the optical path calibration device and a furnace sequentially, then is reflected by the 
optical filter and enters into the optical path calibration device for calibration of the optical path. The combustion detection 
system disclosed by the invention can carry out rapid alignment when a boiler is in a cold state.