The invention discloses a preparation method of 1,3,3,4,4,5,5-heptafluorocyclopentene. The method comprises the following steps of a, under the existence of hydrogenation catalysts, 1,2-dichlorhexafluorocyclopentene and hydrogen gas take a gas phase catalytic hydrogenation reaction to obtain 1-chloro-3,3,4,4,5,5-hexafluorocyclopentene; b, under the existence of fluorination catalysts, 1-chloro-3,3,4,4,5,5-hexafluorocyclopentene and anhydrous hydrogen fluoride take a gas phase catalytic fluorine-chlorine exchange reaction to obtain a product of 1,3,3,4,4,5,5-heptafluorocyclopentene. The method provided by the invention has the advantages that the raw materials of 1,2-dichlorhexafluorocyclopentene can be easily obtained; in addition, the price is low. The zero-pollution production of the 1,3,3,4,4,5,5-heptafluorocyclopentene can be realized; the first step reaction and the second step reaction are performed through a circulation system, so that the reaction of the materials is complete; the sufficient utilization of the materials is realized, so that the pollution is greatly reduced; the zero pollution of the production is realized.