The invention discloses a carbon-modified TiO2/WO3 composite nanofiber photocatalyst, a preparation method and application and belongs to the technical field of nano photocatalytic materials. The preparation method includes following steps: 1), adding polyvinyl pyrrolidone, ammonium tungstate and tetrabutyl titanate into mixed liquid of alcohol and acetic acid, and mixing well before electrostatic spinning to obtain nanofiber felt; 2), calcining the nanofiber felt to obtain TiO2/WO3 nanofiber; 3), adding the TiO/WO3 nanofiber, glucose and water into a reaction kettle, allowing hydrothermal reaction, filtering, cleaning, and drying to obtain the photocatalyst. The TiO2/WO3 composite nanofiber is modified through carbon, a carbon layer on the surface of TiO2 is used as an electron collector, and WO3 is used as an electron hole collector, so that photo-generated carriers can be separated effectively and photocatalytic performance of the photocatalyst can be improved. In addition, WO3 can promote ordering and graphitizing of the carbon layer, so that photocatalytic performance of the photocatalyst can be further improved.