With the continuous expansion of China’s power gird and the deepening harmonic pollution, there is an ever-increasing demand for the simulation analysis of harmonics in power systems. In view of the shortcomings of existing power system digital simulators in terms of the integrity and scalability of harmonic analysis, a harmonic analysis oriented power system digital simulator is investigated and designed by combing computer visualization techniques, Web techniques and power system simulation techniques. By fully considering harmonic analysis and user requirements, both traditional and new harmonic analysis models are supported, SVG and JavaScript are used to support the drawing of one-line diagrams and visualize the results. The feasibility of the harmonic analysis oriented power system digital simulator is verified by an instance. The simulator can achieve multiple types of harmonic analysis, enhance the visualization of harmonic analysis, and has good interactivity and extensibility.