Disclosed in the present invention are a chromium-free gas phase fluorination catalyst and an application thereof. The precursor of the related chromium-free gas phase fluorination catalyst consists of a compound containing iron element, a compound containing rare earth metal element and a compound containing element A, wherein element A is one selected from Ca, Al, Mg and Ti, the precursor is subjected to roasting and fluorination treating to obtain the chromium-free gas phase fluorination catalyst. The precursor of the catalyst is roasted at 400-500° C. and fluoridized with hydrogen fluoride at 350-450° C. to obtain the chromium-free gas phase fluorination catalyst. The catalyst has characteristics of being chromium-free and environment-friendly, good catalytic activity and long life etc. The catalyst can be used for preparing hydrofluoroolefins or hydrochlorofluoroolefins from halohydrocarbons.