H-grade polyesterimide enamelled wire paint was synthesized by transesterification and imidization, and the coating test was carried out on the vertical wire coating equipment with n-butyl titanate modifier as crosslinking agent. According to the moderate crosslinking theory, the effects of seck content and imine content in the formula on the properties of the paint sample were discussed. The test results show that the synthesized polyesterimide enamelled wire paint has the characteristics of good surface leveling, wide wire coating process range, high breakdown voltage, superior thermal shock performance and high softening breakdown temperature, which can meet the needs of high temperature resistant enamelled wire paint in enamelled wire industry.