Herein, a new nanocomposite consisting of up-conversion (UC) material (YF₃:Yb³⁺,Tm³⁺), TiO₂ (P25) and graphene (GR) has been prepared and shown to be an advanced sunlight activated photocatalyst. During the facile hydrothermal method, the reduction of graphene oxide and loading of YF₃:Yb³⁺,Tm³⁺ and P25 were achieved simultaneously, and the functionalities of each part were integrated together. The as-prepared ternary UC–P25–GR nanocomposite photocatalyst exhibited great adsorptivity of dyes, a significantly extended light absorption range, efficient charge separation properties and superior durability. Indeed, the photocatalytic activity of this novel ternary nanocomposite under sunlight was improved compared with those of P25–GR nanocomposites and bare P25. Overall, this work could provide new insights into the fabrication of ternary composites as high performance photocatalysts and facilitate their application in environmental protection issues.