With the continuous development of new network communication, intelligence, unmanned and other technical fields, the marine electric field is becoming a new strategic space for the world"s powerful countries to maintain and expand. Marine electric field detection can play a decisive role in marine resource exploration and development, marine environment monitoring and protection, etc. Integrated electric field sensors have excellent flexibility and adaptability in measuring extremely low frequency electric fields in the ocean, but there are still key technical challenges: the detection of extremely low frequency electric fields requires relatively high sensor sensitivity. In response to this, this paper conducts a sensor structure design simulation study based on the theory of marine electric field distortion, and introduces topology optimization and shape optimization methods to improve the amplitude of the measured electric field. A new electric field sensor structure design scheme is proposed, which effectively improves the sensitivity of the electric field sensor.