Abstract: Offshore wind power industry in China has been developing rapidly in recent years, and particularly with the new proposal of "carbon peak and carbon neutralization", it is entering a new period of steady development. According to the characteristics of offshore wind power engineering, this paper summarizes a large number of engineering investigation practice and research results and wraps up the major engineering geological problems as well as corresponding countermeasures in offshore wind farm construction. This paper mainly introduces four major engineering geological problems, including sea area earthquake and active fault, deep soft soil, special rock and soil and marine geological disaster, with an emphasis on their impacts on the stability of the site, foundation, cable and other structures. Considering the characteristics of these four types of engineering geological problems, marine geophysical exploration, offshore drilling, in-situ test, advanced geotechnical test, physical model test as well as numerical analysis should be incorporated and widely applied to the investigation of different engineering geological problems. The presented investigation and evaluation methods for various engineering geological problems are of great significance on construction and safe operation of offshore wind power in the future.