The invention relates to a trapping method, an extraction method and a determination method for carbonyl compounds and tobacco-specific nitrosamines in mainstream cigarette smoke and belongs to the technical field of physical and chemical inspection of mainstream cigarette smoke. The trapping method for the carbonyl compounds and tobacco-specific nitrosamines in the mainstream cigarette smoke disclosed by the invention comprises the following steps: preparing a pretreatment solution from 0.20mol/L hydrochloric acid and absolute ethyl alcohol according to a volume ratio of 1:1; balancing the pretreatment solution on a standard filter for 2 hours so as to obtain a pretreated filter; and taking the standard filter as an auxiliary filter, enabling the mainstream cigarette smoke to sequentially pass through the pretreated filter and the auxiliary filter, and trapping the carbonyl compounds and tobacco-specific nitrosamines in the mainstream cigarette smoke. According to the trapping method disclosed by the invention, twelve harmful components in the carbonyl compounds and tobacco-specific nitrosamines of the mainstream cigarette smoke can be simultaneously trapped due to one-time smoking, so that the working efficiency is doubled. Moreover, the influence that large dead volume is caused during solution trapping can be eliminated.