The invention relates to a method for detecting chromium, nickel, arsenic, selenium, cadmium and lead in cigarette side-stream smoke. The method is characterized in that a fishtail cover is connected with a quartz fiber filter disc in series to collect particulate matters in the cigarette side-stream smoke, a triple-tandem nitrite acid solution is used for collecting gas phase matters in the side-stream smoke, a microwave digestion method is used for digesting samples, and the contents of chromium, nickel, arsenic, selenium, cadmium and lead in the particulate matter and gas phase matter samples are detected through ICP-MS (Inductively Coupled Plasma Mass Spectrometry). The method overcomes the defects of sample collecting and processing methods and detecting techniques in the prior art and fills the blank of domestic detecting techniques for heavy metal in the side-stream smoke. The fishtail cover is connected with the purified quartz fiber filter disc in series to collect the particulate matters in the side-stream smoke, so that the background interference is effectively reduced. A three-stage absorption bottle collects the gas phase matters in the side-stream smoke, so that the gas phase matters can be completely collected. The microwave digestion method treats the samples, so that the digestion effect is good, and the element loss is few. The ICP-MS is adopted for determination, so that the method is fast and accurate, high in sensitivity, good in repeatability and high in recovery rate.