A large number of human engineering activity facilities are distributed in the Zhuanghe sea area in the eastern Liaodong Peninsula. Therefore, studies on the engineering geological characteristics and exploitation suitability in the Zhuanghe sea area can be helpful for improving the safety and efficiency of offshore engineering exploitations. Based on the data obtained by high-precision marine geophysical surveys, surface sediment sampling and collection of historical engineering geological data, the engineering geological characteristics of the coastal zone in the Zhuanghe sea area are analyzed systematically. The results indicate that at the water depth ranging from 11.5 m to 15.6 m in the study area the seafloor has a small slope and a relatively flat terrain, and under the seafloor there are four continuous acoustic reflection interfaces and some adverse geological factors such as soft soil layers, buried ancient depressions and river channels. The results of the liquid-plastic limit property tests of the surface sediment indicate that the seafloor sediment in the study area is relatively stable and the sinking problem of the soft soils can be ignored. Through the comprehensive analysis of all geological impact factors in the study area, it can be believed that the various environmental indicators in the study area are relatively stable and suitable for carrying out the marine engineering exploitation activities. However, all the detected adverse geological factors should be considered and focused on in the specific construction process.