The invention discloses a water purification device. The water purification device comprises a raw water inlet, a filtration component, a pressure reduction valve, a source water pump and a low-pressure switch. The filtration component is connected with a raw water inlet through a raw water inlet pipe, and the filtration component is used for receiving raw water and filtering the raw water; the pressure reduction valve is connected on the raw water inlet pipe in series to reduce water pressure of the raw water inlet pipe when the situation that the water pressure of the raw water inlet pipe is more than a set range value is detected; the source water pump is connected on the raw water inlet pipe in series to increase the pressure of fluid; the low-pressure switch is arranged on the raw water inlet pipe to detect the water pressure of the raw water inlet pipe so as to control the source water pump to be opened when the situation that the water pressure of the raw water inlet pipe is lower than the set range value is detected. According to the water purification device disclosed by the invention, the excessively high water inlet pressure is reduced by the pressure reduction valve, and the excessively low water inlet pressure is increased by linkage action of the source water pump and the low-pressure switch, so that the water inlet pressure can be stabilized within a working range of the water purification device and the stable operation of the water purification device is ensured.