The invention discloses a smoke detection method, which comprises the steps of: adjusting a detection period of a smoke alarm to be a rapid detection period when a smoke density is detected to meet a set density threshold; calculating a ratio of an electrical signal increment caused by a first transmitted signal to an electrical signal increment caused by a second transmitted signal; and increasing a smoke alarm threshold when smoke is judged not to be caused by a fire hazard based on the ratio. In the invention, different types of smoke can be identified and different alarm modes can be selected to solve the problem of a false alarm.