provided is a method for preparing vinyl chloride with acetylene and dichlorethane for large - scale industrial production . acetylene , dichlorethane vapor and hydrogen chloride gas at a molar ratio of 1 :: are mixed ; the raw mixed gas is preheated ; the preheated raw mixed gas passes through a reactor containing a catalyst and reacts ; the resultant mixed gas is cooled to 30 - 50 ° c . and pressurized to 0 . 4 - 1 . 0 mpa , and then cooled to ambient temperature , and further frozen to − 25 - 15 ° c . for liquefaction isolation , and unliquefied gas is recycled and reused ; liquefied liquid is sent to a rectifying tower for rectification , and vinyl chloride monomers meeting polymerization requirements are obtained . the present invention has the advantages of eliminating mercury contamination completely , simplifying the reactor structure , recycling hydrogen chloride and acetylene , reducing waterwash process , avoiding mass production of waste acid and improving utilization of chlorine .