The invention relates to the water treatment industry, in particular to the potable water filtering aspect, and discloses a single-shaft body device double control water outlet faucet water gap switching control method used for a water purifier. A movable disc placed in a combined shell is matched with a fixed disc in an up-and-down contact manner to form a seal switching interface capable of switching states of all water gaps of the fixed disc at the same time; a water outlet communicated with a faucet water outlet nozzle pipeline is arranged on the fixed disc or arranged on the movable disc; the fixed disc arranged at the closing position is further provided with a water purifying opening or a pure water opening and is connected with a water purifying pipeline or a pure water pipeline of the water purifier; a movable limiting structure for limiting the movable disc moving track forms a moving channel limiting two-time switching moving of the position, corresponding to the closing position of the fixed disc and between the water purifying opening and the pure water opening, of the movable disc; a water outlet connecting channel arranged on the movable disc enables a fixed disc water outlet to be in sealed series connection with the water purifying opening or pure water opening along with two-time switching moving of the movable disc beginning from the closing position.