The novel wollastonite/g-C3N4composites were synthesized via a simple calcination and acid leaching process. The as-prepared photocatalysts were characterized by XRD, HRSEM, PL, UV–vis DRS, ESR and BET. The phtotocatalytic performance of the as-synthesizedcomposites was evaluated by the photodegradation of Rhodamine B under visible light irradiation. The visible-light photocatalytic activity of the as-prepared samples is much higher than that of pure g-C3N4. The Di/Wo(H+)-4:3 sample displays the optimal photocatalytic performance towards RhB under visible light and its reaction rate constant is 6.5 times that of pure g-C3N4. Meanwhile, the Di/Wo(H+)-4:3 presents a good durability and reusability. The improved photoactivity of the Di/Wo(H+) composite could be attributed not only to its high surface area and porosity but also to the synergistic effect of the g-C3N4 and wollastonite, which can effectively promote the separation of photogenerated electron-hole pairs and consequently enhanced its photoactivity.