The invention provides a gas phase fluorination catalyst and a method for preparing the same. The aim of the invention is to provide a gas phase fluorination catalyst with high activity and stability and a method for preparing the same so as to overcome the defects of poor activity and stability existing in the prior gas phase fluorination catalyst. The catalyst of the invention comprises a carrier and active components, wherein the carrier is a compound of Y, and the active components comprise a compound of chromium and one or more of compounds of magnesium, aluminum, indium, gallium and zinc. The method for preparing the catalyst comprises: according to a certain ratio, the compounds of Y and Cr and one or more of compounds of magnesium, aluminum, indium, gallium and zinc are weighed up, added with water, evenly mixed and added with a precipitator until the precipitation is finished, and the precipitate is separated and the solution washed until the filtrate is neutral, the precipitate is dried, formed and roasted to give the a precursor of the fluorination catalyst, and the precursor of the fluorination catalyst is added with anhydrous HF and treated at a certain temperature to give the gas phase fluorination catalyst.