Bypass flowmeter

The invention discloses a bypass flow meter which comprises a body part provided with a flow meter body and a bypass part. The body part is provided with a cavity, a first channel, a second channel, a third channel, a fourth channel, a fifth channel and a sixth channel, and the bypass part is provided with a seventh channel. When the flowmeter body needs to be maintained, the first valve seals the first channel, the second valve seals the second channel, at the moment, liquid does not flow through the flowmeter body, and the liquid enters the third channel from the pipeline, then enters the fourth channel through the third channel and then enters the seventh channel through the fourth channel. The water enters the sixth channel through the seventh channel, reaches the fifth channel and finally flows into the pipeline through the fifth channel; at the moment, under the condition that the whole pipeline system is not interrupted, the flowmeter body can be disassembled, assembled and maintained, and then economi