The invention discloses a phosphorus modified catalyst carrier, a preparation method and application of the phosphorus modified catalyst carrier. The preparation method comprises the following steps: (1) dissolving a modifying agent in alcohol and stirring to obtain impregnation liquid; (2) impregnating the catalyst carrier subjected to pretreatment into the impregnation liquid, stirring and impregnating under a sealed condition, and filtering to remove liquid; and drying and arranging into a tube furnace or a muffle furnace, heating to 500-1000 DEG C at the heating rate of 4-6 DEG C/min in nitrogen gas atmosphere, keeping the temperature for 1-4h, and cooling to room temperature to obtain the phosphorus modified catalyst carrier. At least one active component of sulfates of gold, ruthenium, copper, tin and bismuth, chloride, phosphate, pyrophosphate and ethanediamine is loaded on the phosphorus modified catalyst carrier to prepare a mercury-free catalyst for ethyne hydrochlorination, the initial conversion rate of ethyne is improved by 26-86% compared with that of an unmodified sample, and the selectivity of the generated chloroethylene is more than 99%.