A composite water purification apparatus and method thereof are provided. The composite water purification apparatus includes a container, a sacrificial anode, a photocatalyst anode and a cathode. The container is employed for receiving liquid including water and gas. The photocatalyst anode includes a photocatalyst for conducting a photocatalytic reaction. The cathode is electrolyzed with the sacrificial anode and the photocatalyst anode. The cathode, the sacrificial anode, and the photocatalyst anode are immersed in the container to contact the liquid. The present invention enhances the purity of the water, while prolonging the service life of the sacrificial anode.