We present here a tri-phase transfer catalysis synthesis of Sec-butyl disulfide using sec-butyl bromine, sulfur and sodium sulfide nonahydrate as the raw material, the self-made SiO2-g-PS load of quaternary ammonium salt as the tri-phase transfer catalyst. Via the orthogonal experiment, the optimum conditions were obtained as follows: n(Na2S):n(RBr)=1:0.8, the dosage of catalyst is 0.75%,reaction temperature 30℃, reaction time 9h. Repeated the experiment 3 times, the mean of yield is 57.65%. Compared with other tri-phase transfer catalyst, the catalyst this experiment used has the best catalyst effect. What's more, by repeated use 6 times, the catalytic activity did not significantly reduced. The product was confirmed by 1HNMR and FTIR.