The invention discloses a water sample collection device provided with a tube change mechanism. The water sample collection device comprises a collection tube, a screw rod, a guide rod, a mounting plate, a connecting plate, a rubber sleeve, a rotating table, test tube covers, sampling test tubes, a lifting motor, a rotating motor, a control box, a controller, a GPS (global position system) locator, a wireless communicator, a camera and the like. The collection mechanism and the tube change mechanism are arranged, so that each of the sampling test tubes can be conveniently inserted into a rubber tube in the collection tube for water sample collection work, the sampling test tubes are changed by the rotating table and the motors, water samples in lakes can be automatically collected, and the test tubes can be automatically changed. Therefore, the labor intensity of workers is effectively relieved, and the collection of the water samples of the lakes is facilitated; the GPS locator and the wireless communicator are arranged, so that position information of collection of the water samples is sent to a far-end server, so as to complete recording; the camera is arranged, so that the test tubes for collecting the water samples at different positions and different times can be photographed and recorded, so that the workers can conveniently distinguish a plurality of sampling test tubes in the rotating table.