The invention discloses a gas chromatography-tandem mass spectrometric detection method of migration quantity of a bactericide in cigarette mainstream smoke, comprising the following steps: (1) pumping cigarette by a smoking machine, and capturing mainstream smoke's total particulate matter by the use of a Cambridge filter; (2) cutting the Cambridge filter and putting the cut Cambridge filter into a centrifuge tube, adding acetonitrile and internal standard solution, and oscillating until a sample is impregnated; (3) adding a solid-phase extraction reagent, oscillating and carrying out centrifugal separation; (4) taking a supernatant obtained after the centrifugation in the step (3) and putting the supernatant into a purification centrifugal tube, oscillating and carrying out centrifugal separation; and (5) analyzing the supernatant obtained after centrifugation in the step (4) by gas chromatography-tandem mass spectrometric detection.