Abstract: Fish oil has many dietary benefits, but due to their strong odors and rapid deterioration rates, their application in food formulation is limited. This article reported a systematic study of encapsulation of fish oil into PPI-GA microparticles by emulsification and subsequent freeze drying in order to protect it from lipid autoxidation and facilitate its incorporating into healthy food. According to the single factor experiment result, four factors and three levels experiments were designed with the encapsulation rate as index, and the optimized experimental conditions were as follows:wall material mass fraction 5%, mass ratio of PPI to GA 1:1, homogenization pressure 50 MPa, and core-wall ratio 1:2. Under this condition, the encapsulation rate of fish oil microcapsules was 78.10%, the moisture content, angle of repose, and bulk density were (1.94±0.08)%, (41.40±0.25)° and (0.11±0.02) g/cm³, respectively. the fish oil package was determined by gas chromatography. The retention rate of DHA before and after encapsulation was 95.33%. The relationship between the quality of fish oil microcapsule products and temperature was analyze by TG analysis. The results showed that the pyrolysis process was divided into two stages, the first stage occurred at 189.61-255.10℃, when the microcapsule wall material underwent violent physicochemical reactions. The second stage occurred at 255.10-396.01℃, which was the accelerated stage of weightlessness, at this stage, the core material may be completely decomposed and finally carbonized. The fish oil microcapsule products were stored in a constant temperature incubator at 4, 25 and 35℃ for 21 days, and the peroxide value was measured every 3 days. The Arrhenius empirical formula was used to analyze the oxidation kinetics of fish oil microcapsules and the Vant'Hoff empirical formula was used to predict the shelf life of the microcapsule products. The results showed that the shelf life of fish oil microcapsules under 4℃ storage conditions was 176 d, and the microencapsulated fish oil performed prolonged shelf life than normal fish oil. The releasing of fish oil microcapsule products under different temperature and humidity conditions was studied. An appropriate number of microcapsules was taken every 3 days to determine the core material retention rate, and the Avrami's formula was used to analyze the core material release process. The results showed that with the increase of temperature and humidity, the release of fish oil microcapsules gradually increased, and high temperature and high humidity conditions were not conducive to the retention of core materials.