The invention discloses a ruthenium-based catalyst used for producing vinyl chloride through acetylene hydrochlorination, wherein the ruthenium-based catalyst is prepared by using a freeze drying method, such that the influence on the stability of the catalyst due to the migration of the active component in the pore channel of the catalyst onto the carrier surface along with the volatilization ofthe water during the preparing in the catalyst in the common vacuum drying method is avoided. According to the present invention, with the application of the ruthenium-based catalys in the vinyl chloride production through acetylene hydrochlorination, the ruthenium-based catalyst has high stability, the ruthenium loss is not detected within the detection limit of the detector after the long-time operation for 8000 h, the acetylene conversion rate can be up to 99.8%, and the vinyl chloride selectivity can be up to 100%.