Haikou Meilan International Airport expansion project is a major infrastructure construction project that Hainan serves the national “Belt and Road” strategy, the gateway airport of Hainan Free Trade Port, and plays the role of the fulcrum of the Maritime Silk Road. Combined with geotechnical engineeringGeotechnical engineering investigation of Haikou Meilan International Airport extensionAirport extension airfield area project, the topography, engineering geological conditions and hydrogeological conditions of the airfield area are identified. Through the comprehensive geophysical exploration combining seismic reflection wave method and high density electrical method, the spatial structure and engineering characteristics of the rock and soil layer are further found out, and multiple means are used to confirm each other to ensure the reliability of the survey data. Through the analysis and evaluation of engineering geology, hydrogeology and geophysical exploration in the airfield area, the geological condition parameters are put forward to provide scientific basis for design, construction and detection.