Coaxial capacitive voltage divider shows good stability ,can effectively avoid the influence of parasitic capacitance, resistance to electromagnetic interference.Distribution of electric field is not uniform in coaxial capacitive,dielectric strength related to the radius of the coaxial capacitance. The selection principles of the radius of the coaxial capacitance are presented in this paper.At the same time, the influence of temperature on the accuracy of capacitive voltage divider is related to its structure. This paper establishes a mathematical model to analyze the influence of inner and outer radius,thickness of cylinder,expansion coefficient,temperature on the accuracy.Calculations and computer simulation results show that the key to enhance the accuracy of capacitor divider is to keep the ratio of inner and outer radius e , choose metal material of low expansion coefficient , proper thickness of cylinder and larger radius . In that case,the coaxial capacitive will has the best insulation characteristic.