The supported SnCl4 catalyst was prepared using activated carbon as the carrier. Different contents of BiCl3 and CuCl2 were added into SnCl4 catalyst as assistant in order to study the effect of assistant on the catalytic performance of acetylene hydrochlorination. The results showed that when the ratio of BiCl3⁃CuCl2⁃SnCl4 was 5%,10%,10%.The catalyst showed the highest activity for acetylene hydrochlorination. The conversion of acetylene can reach 94% under the conditions of hydrogen chloride/acetylene ratio 1∶1.1, reaction temperature 170 ℃ and GHSV(C2H2) of 60 h-1. The characterization results showed that the introduction of additives inhibited the loss of Sn during the reaction and thus improved the stability of the catalyst. Finally, the activity of Sn based catalyst was effectively improved.