To make better use of solar light, a new Bi2WO6/Cu1.8Se photocatalyst active to visible and near-infrared light has been synthesized by a facile hydrothermal method. The composites were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), UV-vis diffuse reflectance spectroscopy (DRS), and photoluminescene (PL). The photocatalytic activities of Bi2WO6/Cu1.8Se are evaluated by degrading Congo red solution and hydrogen generation from water. It was found that the molar percentage of Cu1.8Se had great effects on the morphology and photocatalytic property of the Bi2WO6/Cu1.8Se heterojunctions, and the composite with suitable molar amount of Cu1.8Se exhibits much enhanced photocatalytic activity for Congo red degradation under visible and near-infrared light irradiation and for hydrogen generation under visible light compared to Bi2WO6. The significant improvement photocatalytic activity of the composite could be attributed to its good light absorption, suitable band gap structure, and effective separation of photogenerated electron-hole pairs of Bi2WO6/Cu1.8Se heterojunction. This work presents an efficient multifunction photocatalyst owning the activity both for water splitting under visible light and for organic contaminants decomposition under visible-near-infrared light.