This book is based on the basic teaching requirements of higher vocational colleges, with the goal of cultivating high-end skilled talents in the production line. Based on the principle of "teaching the basic principles thoroughly, laying a good circuit foundation, and oriented to circuit analysis", it is necessary, practical, and sufficient to highlight the characteristics of vocational education and strengthen practical teaching links. This book is divided into two parts, the basic part and the electrician skills training part. The content is compiled according to eight learning projects, including the analysis and application of DC circuits, the installation and debugging of single-phase AC circuits, the installation and debugging of three-phase AC circuits, the analysis and observation of circuit transition processes, the application and testing of magnetic circuits and core coil circuits, safe electricity use, basic knowledge of commonly used electrical tools and instruments, and practical training projects. Each project in the first chapter has task introduction, task information, task implementation, task evaluation and training question set.