The aim is to prepare a kind of sodium alginate microcapsules which could slowly release fish allergens. The spherical alginate microcapsules were prepared by the ionotropic gelation method and the microcapsules were formed by adding sodium alginate into aqueous solution containing calcium chloride. The prepared microcapsules were characterized by FTIR, DSC and SEM methods. The releasing mechanism of parvalbumin from the microcapsules was established based on equation fitting of release kinetics model. Parvalbumin could be embedded into alginate microcapsules. The entrapment efficiency was 69.24% while the loading ratio was 21.06%. The surface of microcapsules which had plenty of tiny holes was rough. The result of protein release in vitro showed that parvalbumin released rapidly in the first 5 hours, and then gradually achieved maximum. The release kinetics model suited Higuchi equation and Ritger-Peppas equation well. Fish allergen could be entrapped by sodium alginate, meanwhile allergen controlled-release was achieved. The mechanism fits with skeleton erosion in addition to protein diffusion mechanism.