Safety helmet

The present invention provides a safety helmet. The safety helmet comprises a housing; an interlayer is disposed below the housing; a cavity is disposed between the housing and the interlayer; the top of the interlayer is provided with an air inlet; the rear end of the housing is provided with an air outlet; the air outlet is provided with an axial fan; and an adjustable shift device and a battery are disposed near the axial fan. According to the safety helmet, temperature of the head of a worker can be reduced in hot, humid and enclosed environment, relatively appropriate working environment is provided for the workers, working efficiency and construction quality of the workers are also improved, and the number of the workers suffering from heatstroke or anemopyretic cold is reduced.