The invention discloses a method for measuring benzo(a)pyrene in total particle phase matters in a cigarette smoke gas, which comprises the following steps of: preparing solution of D12-benzo(a)pyrene as internal standard solution, wherein the concentration of the solution is between 100 to 300 ng/ml; preparing six standard series solution of the benzo(a)pyrene; collecting the total particle phase matters in the cigarette smoke gas, and adding cyclohexane into the total particle phase matters to perform ultrasonic extraction; adding an extraction liquid into the internal standard solution of the D12-benzo(a)pyrene to perform vacuum concentration, and performing GC-MS analysis on a sample after the vacuum concentration; and performing internal standard method quantification. The method overcomes the defects that in the prior art, a non-target compound has large interference to a target compound, the sample pretreatment process is complex and the analysis time is long; and the method for measuring the benzo(a)pyrene in the total particle phase matters in the cigarette smoke gas is provided by the invention, which reduces the interference of the non-target compound to the target compound, simplifies the sample purification process, is more accurate in quantification, has a high recovery rate and good repeatability and can be widely applied in the field of tobaccos.