The invention discloses a swimming pipe for testing fish tolerance to a dissolved gas, and belongs to the field of fish tests. The swimming pipe comprises: a power device and a main pipeline. The swimming pipe disclosed by the invention has the following advantages: (1) different flow rates can be controlled, and a swimming ability test on the fish is conducted independently; (2) the swimming pipealso can be arranged in a closed water tank to measure the fish tolerance to a water body saturated with dissolved gas at a specific flow rate; (3) activities of the subject fish can be observed relatively well; (4) under the effects of water inlet rectifying grids and water outlet rectifying grids as well as flow dividing holes and an equalizing plate, the swimming pipe can reduce the rotation flow caused by a propeller.