There are varying degrees of seawater intrusion in High tech Marine Economic New Area in eastern Yantai city. It has potential impacts on the planning and development of the new area. Through analyzing water quality of groundwater samples at monitoring points, by using Cl ,TDS and sodium adsorption ratio (SAR) as a parameter in the fuzzy mathematical comprehensive evaluation model, the boundary of seawater intrusion degree has been divided by using high-density electrical method. The fuzzy comprehensive evaluation of seawater intrusion degree has been carried out on 153 monitoring points in the eastern new area of Yantai city. The problem of seawater intrusion has been further analyzed, and countermeasures have been proposed to ensure smooth progress of coastal zone construction in the eastern new area of Yantai city and provide scientific basis for sustainable development of the new area's economy.