The invention belongs to the field of medical apparatuses and instruments and relates to a suction device for a laparoscopic surgery. A suction cannula comprises a cannula wall, a cannula head end anda cannula tail end. A cannula wall air outlet is formed in the cannula wall, and supporting arris are arranged on the inner side of the cannula wall. A cannula main body structure composed of the cannula wall and the air outlet surrounds a laparoscope instrument to form a relatively airtight gap, and accordingly air is sucked into the cannula head end and is sucked out of the air outlet through an external suction cannula. A use result shows that the laparoscope instrument suction cannula is simple and clear in design, simple in making process, good in practicability and good in convenience,can be disposable or be used after being repeatedly sterilized and can effectively improve the quality and efficiency of the laparoscopic surgery. In addition, the diameter size of the laparoscope instrument suction cannula can be flexibly adjusted, and any matching between the laparoscope instrument suction cannula and various laparoscope operating instruments in use is achieved.