The present invention discloses a fluid purification and disinfection system, which includes a housing, an ultraviolet lamp and a photocatalytic oxidation device. Said housing therein is an enclosed case that is fitted with an inlet and an outlet. Furthermore, said ultraviolet lamp is mounted inside the housing. Said photocatalytic oxidation device is a disinfection core coated with photocatalyst. Said disinfection core is installed around said ultraviolet lamp, and is fixed onto said housing. Said photocatalyst therein is titanium dioxide. The working principle of the fluid purification and disinfection device in accordance with the present invention is to utilize ultraviolet light to irradiate the titanium dioxide-coated surface of the photocatalytic oxidation device to generate the photocatalytic oxidation process. As a result, Escherichia coli, Vibriocholerae and pathogenic organisms that contact the surface of photocatalytic oxidation device can be quickly killed, and contaminants in the fluid can be eliminated. By this way, water or fluid that flows through said disinfection device is disinfected and purified.