The invention discloses a novel process of sargassum fusiforme arsenic removal, sargassum fusiforme is firstly cleaned for three times by warm water which is about 50 DEG C, then being broken into small segments which are 10mm-50mm, and then being put into an enzymatic hydrolysis pot, in which 8-20 times water and 0.1-1 percent of ethylene dinitrilotetra-acetic acid are added, and the temperatureis increased to about 50 DEG C and is kept for 30-60 minutes. The technology of the invention greatly reduces the arsenic content in the sargassum fusiforme, and provides safety assurance for safely eating and developing related products of the sargassum fusiforme. The method of the invention is scientific, simple, easy, safe and effective, and is convenient for industrial continuous operation. New pollutants are not introduced, new un-safe matters are not produced, and the invention is better than the prior arsenic removal technology.