Abstract: This patent relates to a smoke evacuation tube and a telescopic smoke evacuation scalpel comprising the smoke evacuation tube. The smoke evacuation tube, comprises a first sleeve (6) and a second sleeve (26). An electrode (8) is mounted inside the first sleeve front section (61), and one end of the electrode (8) protrudes from one end of the first sleeve front section (61); the diameter of the first sleeve (6) is greater than the diameter of the second sleeve (26); a engaging structure used for assembling a lower conductive piece (7) is provided on or outside the second sleeve (26) and inside the first sleeve (6). The telescopic smoke evacuation scalpel comprises an upper conductive piece (10), which is embedded on the pencil body (4); the end of the first sleeve rear section (62) distant from the first sleeve front section (61) is provided with a connection hole.