WS2/TiO2 composite was prepared by using the ultrasonic dispersion method, and the effect of degradation of Rhodamine B was studied under irradiation conditions. The influence factors on the degradation efficiency, such as calcination temperature and time of WS2/TiO2 , the amount of catalyst, illumination time, irradiation intensity, and initial concentration of Rhodamine B were discussed, respectively. The experimental results revealed that the best degradation efficiency of Rhodamine B based on the amount of catalyst was 1.00 g/L, the initial concentration was 10.00 mg/L, the m(WS2):m(TiO2) was 1:11, and the calcination temperature and time were 350 °C and 90 min, respectively.