The invention discloses an oxygen-modified catalyst carrier, and a preparation method and application thereof. The preparation method comprises: (1) dissolving a modifier in water, stirring for dissolving, so as to obtain a dipping solution; (2) dipping a pretreated catalyst carrier into the dipping solution, performing sealed stirring and dipping, filtering, drying, putting in a tubular furnace or a muffle furnace, heating to 500-1000 DEG C in a nitrogen atmosphere at a heating speed of 4-6 DEG C, keeping for 1-4 h, cooling to room temperature, adding a nitric acid aqueous solution, stirring and filtering, so as to obtain a filter cake; and (3) washing to be neutral, and drying. The oxygen-modified catalyst carrier is employed for supporting at least one active composition of sulfates, chlorides, phosphates, pyrophosphate and ethylene diamine complexes of gold, ruthenium, copper, tin and bismuth, so that a mercury-free catalyst for a hydrochlorination reaction of acetylene is prepared, and the catalyst enables the initial conversion rate of acetylene to be improved by 10%-60% compared with an unmodified sample, and the selectivity for generating vinyl chloride is larger than 99%.