A method for making a carbon fiber wheel rim includes: preparing an outer supporting piece; winding a carbon-fiber yarn around the outer supporting piece to form carbon fiber layers and to constitute an engaging seat preform; connecting an inner supporting piece to the engaging seat preform; connecting a reinforcement piece to the inner supporting piece; winding a carbon-fiber yarn around an assembly of the engaging seat preform, the inner supporting piece and the reinforcement piece to form carbon fiber layers; fixing the assembly with the carbon fiber layers to form an outer frame preform; and cutting the outer frame preform and the engaging seat preform to form a trench and removing the outer supporting piece therefrom.