A single?mode focused microwave synthesis system was used to rapidly synthesize MIL?53(Fe).The effect of reaction additive hexadecyl trimethyl ammonium bromide(CTAB) on the crystal structure, morphology, and particle size of MIL?53(Fe), as well as the microwave synthesis conditions on catalytic performance of MIL?53(Fe) were investigated using 10 mg/L Rhodamine B as a target contaminant. The results show that the addition of CTAB reduces the size of MIL?53(Fe) and makes the shape more regular. When the microwave power is 75 W,the temperature is 100 ℃,the synthesis time is 1 h,n(FeCl₃·6H₂O)/n (CTAB)=1∶0.5,the catalyst dosage is 0.2 g/L,the degradation rate of Rhodamine B can be more than 90% in 100 minutes under the radiation of 300 W tungsten lamp. It was known from free radical capture experiments that holes and ·OH were the main active species in the photocatalytic process.