Due to the development trend of marine engineering and the limitation of the existing research results, to obtain the concrete destruction rules and influence factors in open sea conditions, the offshore field exposure station was established, the site-selecting principles and site characteristics of which were expounded in this paper. The exposure test and research results were of great significance for enhancing the durability of concrete in open sea from the design, maintenance and management, and ensuring the safety and long-term durability of offshore large infrastructures.