A method and device for detecting sleep apnea, which overcome the current defect that it is hard to distinguish the type of sleep apnea. The method comprises: monitoring the instantaneous output power and the instantaneous rotational speed of an electric motor conveying air in a breathing device (S110) according to the instantaneous output power and the instantaneous rotational speed of the electric motor, obtaining an airway flow reference value representative of the air in an upper airway of a user using the breathing device (S120) when it is determined that the user is currently not spontaneously breathing and the duration has reached a pre-set time threshold value according to the airway flow reference value, determining that the user is in an apnea state (S130) judging whether the upper airway of the user is clear (S140) and determining that the apnea of the user is central apnea (S150) or obstructive apnea (S170) depending on whether the upper airway of the user is clear. The method and device can accurately and effectively distinguish the type of sleep apnea.