Due to the little field for the construction of coastal port construction at present, there is a need to construct large infrastructures such as harbor, bridge, tunnel and wind turbine along the coast with a worse natural condition. As a result, the bad sea conditions such as heavy wave, rapid current, deep water and huge wind are encountered for the coastal investigation work. On the other hand, the comprehensive investigation technologies adapting the high standards and strict requirements are required for the large infrastructures to find out the complex geological conditions. The traditional and single overwater investigation technologies are hard to satisfy the requirements of the large project’s construction, and the new investigation technologies are necessitated to be sought for. Taking the investigation technology of CCCC-FHDI Engineering Co., Ltd. as an example, this paper reviews the process of the coastal investigation technology and prospects to enhance the international competitiveness, which will provide reference for the promotion of the domestic coastal investigation technology and participate in the international competition.