Fire detection method, device and system and train

The invention provides a fire detection method. In the process of fire detection, a first trigger signal can be acquired first. The first trigger signal is determined according to a first parameter detected by a first sensor, the first parameter represents the smoke concentration detected by the first sensor, and the first sensor is located in a first area. The first trigger signal represents thepossibility of fire in the first area. If a second trigger signal is acquired within a first time interval after the first trigger signal is acquired, that fire occurs in the first area is determined.The second trigger signal is determined according to a second parameter detected by a second sensor, the second parameter represents the smoke concentration detected by the second sensor, and the second sensor is located in the first area. Thus, the situation of the same area is detected through different sensors, the probability of misjudging fire is reduced, and the accuracy of fire detection is improved. In addition, t