Abstract: According to explosion-proof principle and requirement of safety certification mark, this paper analyzes the problem which possibly appears during the production checking and intrinsic safety explosion test. By resolving the circuit consisting of low-dropout regulator, the technical factors influencing the stability of intrinsically safe circuit have been presented. The paper also suggested corresponding solution based on analysis of the discreteness of low dropout regulator, the temperature-drift characteristics of limiting current, differential pressure distribution, max output capacity, heat dissipation, and related electrical specification. In the end, the paper lists all the notice during the design of intrinsically safe circuit, safe explosion-proof test, and manufacturing process.