This paper presents a built-in transient data recording scheme for control and protection system in UHVDC project. This scheme contains a set of transient data recording software, which can be ported to any control and protection equipment quickly. With this function, the device not only can record the operating data from the inside of the device, but also can record external data by way of using a variety of communication methods and communication protocols, and generate waveform files in Comtrade format according to international standards. This scheme has the characteristics of flexible configuration, comprehensive function, various forms of storage and transmission ways, easy to use, and can assist the engineering personnel to locate the system fault rapidly, evaluate the experimental results of the system, and analyze any problems encountered in the system joint debugging. This work is supported by National Key Research and Development Program of China (No. 2016YFB0900600) and Science and Technology Project of State Grid Corporation of China (No. 52094017000W).