In order to solve the problems of low entrapment ratio and limited controllbility during isocyanate self-healing microcapsules (SHM) preparation, an interfacial polymerization strategy for preparing SHM was proposed utilizing polyurethane prepolymer as wall material. In detail, polyurethane prepolymer (Bayer L-75) and 1,4-butanediol (BDO) were used to prepare the wall material and isophoroned diisocyanate (IPDI) was selected as core material.The interfacial polymerization occurred between isocyanate group (-NCO) of L-75 in oil phase and hydroxyl group (-OH) of 1,4-butanediol in aqueous phase, during which polyurethane film was generated to encapsulate core material. The influences of the amount of emulsifier and BDO on the performance of microcapsules were discussed. Chemical structures of the microcapsules were characterized by FT-IR. The surface morphology size distribution was investigated by optical microscope.The core content of microcapsules was studied by thermogravimetric analyzer (TGA). The results show that the mass fraction of the core material of 55.69% and entrapmentratioof 83% are achieved when the feed ratio of curing agent 1,4-butanediol is fixed at 11.7%, emulsifier gum arabic at 17.4%, IPDI at 67% and stirring speed is kept at 600 r/min.