The utility model discloses an in-tube solid-phase micro-extraction system comprising a gas source connected with a constant pressure valve. The other end of the constant pressure valve is connected with a three-way valve. Other two ends of the three-way valve are connected with an output end of a multi-channel micro-flow peristaltic pump and a steel pipe column. One end of the steel pipe column is provided with a stainless steel nut connector; the other end of the steel pipe column is connected with the input end of a capillary integral column through a PEEK connector; the output end of the capillary integral column extends into a receiving bottle used for containing solution. The input end of the multi-channel micro-flow peristaltic pump is respectively connected with a sample solution bottle, a column washing bottle and a resolving solution bottle. The gas source is provided with a booster, or the gas source without a booster is provided with an added pneumatic amplifier pump. The in-tube solid-phase micro-extraction system has the advantages that equipment is simplified, cost is reduced, online automatic operation of a whole extraction process can be achieved through the system used with most analyzers, cross infection is avoided, extraction efficiency is improved, and method reproducibility is improved.