As an important component part of the financial safety net, the deposit insurance system plays a unique role in protecting the medium and small depositors' profits, and maintaining the well-functioning of the financial system. China will establish a deposit insurance system as an important task of the recent financial industry. This paper from the perspective of economy, analyzes rationally of the benefits and costs of the deposit insurance system with the view of thinking the reasonable control of the costs is important to the development of the system effectiveness. Based on the above analysis, provides the corresponding policy recommendations to the rational design of the deposit insurance system in our country.