A cartridge type valve core structure of a water tap includes a cartridge casing and a valve core. The cartridge casing has an accommodation room therein. An outer wall of the cartridge casing is provided with a first engaging portion for connecting with the water tap. The valve core is disposed in the accommodation room. The valve core includes a control end, a water inlet end, a water outlet end, and at least one water room. The control end extends out of the cartridge casing from a top end of the accommodation room. The water inlet end extends out of the cartridge casing from a bottom end of the accommodation room. The water outlet end extends out of the cartridge casing from one side of the accommodation room. Through the aforesaid modular structure, the valve core can be mounted to the water tap quickly through the cartridge casing.