A water purification system, comprising: a composite filter cartridge assembly comprising a filter casing and a composite filter cartridge disposed in the filter casing, wherein the filter casing has a raw-water inlet, a pretreated-water outlet, a pretreated-water inlet, a purified-water port, a purified-water outlet and a concentrated-water outlet, the composite filter cartridge comprises a filtering part and a mouthfeel-improving filter cartridge, the filtering part comprises a pretreating filter cartridge and a fine filter cartridge which are disposed in sequence from outside to inside and spaced apart from each other, the filtering part and the mouthfeel-improving filter cartridge are arranged along an up-and-down direction, the purified-water outlet is communicated with a water-output end of the mouthfeel-improving filter cartridge, the mouthfeel-improving filter cartridge is connected to the fine filter cartridge and is located at the downstream of the fine filter cartridge, the pretreated-water outlet is communicated with a water-output end of the pretreating filter cartridge, the pretreated-water inlet is communicated with a water-input end of the fine filter cartridge, the purified-water port is communicated with a water-output end of the fine filter cartridge and communicated with the water-input end of the mouthfeel-improving filter cartridge; a booster pump having a first end connected to the pretreated-water outlet and a second end connected to the pretreated-water inlet, wherein the booster pump is configured for transporting water flowing out of the pretreated-water outlet to the pretreated-water inlet; a waste-water solenoid valve connected to the concentrated-water outlet; and a water storage device (91, 92, 93) connected to the purified-water port and configured for storing purified water flowing out of the purified-water port, the water storage device (91, 92, 93) being connected to the purified-water port and configured such that water can flow into water storage device (91, 92, 93) from the purified-water port and such that water can flow from the water storage device (91, 92, 93) to the purified-water port. a composite filter cartridge assembly comprising a filter casing and a composite filter cartridge disposed in the filter casing, wherein the filter casing has a raw-water inlet, a pretreated-water outlet, a pretreated-water inlet, a purified-water port, a purified-water outlet and a concentrated-water outlet, the composite filter cartridge comprises a filtering part and a mouthfeel-improving filter cartridge, the filtering part comprises a pretreating filter cartridge and a fine filter cartridge which are disposed in sequence from outside to inside and spaced apart from each other, the filtering part and the mouthfeel-improving filter cartridge are arranged along an up-and-down direction, the purified-water outlet is communicated with a water-output end of the mouthfeel-improving filter cartridge, the mouthfeel-improving filter cartridge is connected to the fine filter cartridge and is located at the downstream of the fine filter cartridge, the pretreated-water outlet is communicated with a water-output end of the pretreating filter cartridge, the pretreated-water inlet is communicated with a water-input end of the fine filter cartridge, the purified-water port is communicated with a water-output end of the fine filter cartridge and communicated with the water-input end of the mouthfeel-improving filter cartridge; a booster pump having a first end connected to the pretreated-water outlet and a second end connected to the pretreated-water inlet, wherein the booster pump is configured for transporting water flowing out of the pretreated-water outlet to the pretreated-water inlet; a waste-water solenoid valve connected to the concentrated-water outlet; and a water storage device (91, 92, 93) connected to the purified-water port and configured for storing purified water flowing out of the purified-water port, the water storage device (91, 92, 93) being connected to the purified-water port and configured such that water can flow into water storage device (91, 92, 93) from the purified-water port and such that water can flow from the water storage device (91, 92, 93) to the purified-water port.