Introduction  Offshore wind farm has been gradually developed with the strong support of China goverment. As the most important structure of offshore wind farm, offshore substations should be paid attention. Due to the wide range adaptability to water depth, most of the foundation of offshore substations has been currently used as jacket. According to the different connection between the jacket and pile, it was divided into skirt pile jacket and conventional jacket.

  Method  Based on past experience, the skirt pile jacket was generally used in the deep water area (more than 40 m). In this paper, based on the construction and design of skirt pile jacket, the author compared the design with the conventional jacket under the regional geological conditions of one project.

  Result  The results show that compared with the conventional jacket, the skirt pile jacket of offshore substation can reduce the length of the pile and the section of the jacket bar, thus the steel material is reduced and the cost is saved.

  Conclusion  The research results have much significance in modularization development of offshore substation.