Abstract: With the implementation of the Nine-Unification requirements by State Grid and the increasing demands for reliability and autonomous controllability in power grid operations, dispatchers have put forward new requirements for the transformation of 220kV line relay protections. In response to these new requirements, adaptive optimization is needed. Taking the practice of transforming 220kV line relay protections in a 220kV substation as an example, this article focuses on the optimization content in terms of protection model, setting value differences, automation coordination, and on-load testing, starting from traditional work of transformation of 220kV line relay protections. This provides guidance for future work.