The invention discloses a flowmeter process. The flowmeter process comprises a flowmeter body, the flowmeter comprises a shell head, a tail vane fixedly connected with a shell head, and a velocity measurement probe; and a cyclone detection device is further arranged at a rear part of the tail vane. By adding a cyclone paddle at the tail part of the conventional flowmeter, the lateral and tangential water flows can drive the paddle to move when the cyclone occurs at the water flow, and the motion data is acquired through a reading unit arranged in the flowmeter; the lateral and tangential change heights of the water flow can be accurately acquired by utilizing the flowmeter disclosed by the invention at different depths of water.