Abstract: In order to decrease the level of deep charged in the spacecraft organic dielectric and improve the stability and life span of the spacecraft.The effects of grounding modes and conductance property on the space dielectric were analyzed.It shows that the non-linear conductance modification can decrease the level of deep charged.The modification to the commonly used spacecraft dielectric was tested,and the preconceived non-linear conductance property was gained.The non-linear conductance modification was considered to be one of the most effective protection methods in deep charged for the dielectric material.