The work aims to prepare the microcapsule antifouling agent embedding cuprous oxide to prolong the antifouling period and reduce environmental pollution. The PEG-Cu2O microcapsule was prepared by single coacervation to coat the cuprous oxide with polyethylene glycol based on the synthesis of cuprous oxide by reduction of glucose. Characterization and composition of microcapsules were investigated with SEM, TEM and FT-IR. Particle size distribution and embedding rate of the PEG-Cu2O microcapsules were determined by PSA and TGA. The release property of microcapsules was explored based on the determination experiment of copper-ion release rate. The effects of PEG addition method, coagulant addition method, reaction temperature and agitation speed on microcapsules were discussed by single factor optimization analysis experiment and SEM topography test. PEG-Cu2O microcapsules with uniform participle size was prepared successfully. The average particle size was 1.66 μm, the average thickness of the capsule wall was 200 nm and the embedding rate was 78.1%. Compared with Cu2O antifoulant, the release properties of microcapsules were more obvious. More ideal microcapsules could be obtained when the experimental method of premixing PEG with copper chloride was adopted, coagulant solution was added drop by drop, reaction temperature was 70 ℃, mixing speed was 200~300 r/min. The microcapsules can effectively control the releasing speed of antifoulant, reduce the pollution and prolong the antifouling period. The simple method is easy and accorded with the concepts of atomic economics and green chemistry and has certain application values in the field of marine antifouling.