The invention relates to water treatment, and provides a water purification three-joint single-valve metering filtration faucet below a kitchen table. The water purification three-joint single-valve metering filtration faucet comprises a faucet body, a filter element, a three-inlet two-outlet valve, a water outlet pipe, a shell and a liquid flowmeter, wherein a cold water inlet channel, a hot water inlet channel, a cold water outlet channel and a water purification outlet channel are formed on the lower portion of the faucet body, the cold water outlet channel and the water purification outletchannel penetrate the lower portion of the faucet body, the liquid flowmeter is arranged in the shell, a water inlet and a water outlet of the liquid flowmeter are arranged in the faucet body in a penetrating mode, one end, far away from the faucet body, of the water purification outlet channel is detachably and hermetically connected with the water outlet of the filter element, the water purification outlet channel is located in the faucet body, one end of the water purification water outlet channel communicates with the water inlet of the liquid flowmeter, the water outlet of the liquid flowmeter communicates with one end of a second water outlet channel in the faucet body, and one end, far away from the liquid flowmeter, of the second water outlet channel communicates with an inner pipe of the water outlet pipe. The water purification three-joint single-valve metering filtration faucet solves the problems that an existing water purification faucet filter element is continuously impacted by water supply water pressure, easy to damage and large in occupied space.