The 5 000 MW power collected by Zhangbei UHV substation put into operation at the end of 2020 is new energy. From the perspective of uncertainty of new energy output, the power flow of Zhangbei-Beijingxi line will change between 0 MW and 5 000 MW. Aiming at the uncertainty, a complete set of UHV hierarchical controllable shunt reactor (CSR) is applied for the first time. It solves the contradiction between reactive power compensation and limiting overvoltage on different requirements of shunt reactor in UHV transmission system, reduces reactive power loss, improves the flexibility of system regulation, and creates favorable conditions for the export of new energy in Zhangbei area. In the process of realizing the application of the first UHV CSR demonstration project, a series of innovative achievements have been made in integrated design and equipment development. The project selection starts with the problems of frequent and large voltage fluctuation on the UHV channel of new energy export. In the integrated design, the intensive design concept of CSR and thyristor valve lays the foundation for economy. These innovative achievements in the power system test stage and more than one year of actual operation of the UHV CSR are analyzed and summarized, and the optimization direction is put forward.