Abstract: The interaction between high voltage solar array and space plasma is a complex nonlinear process,which is dominated by the sheath of metal interconnects of solar array.In order to study the effect of secondary electron emitting from cover material on the sheath,a simplified three-dimensional model of insulator-conductor was constructed.Then through method of particle-in-cell(PIC) and asymptotic boundary conditions the effects of secondary electron emitting on sheath was investigated.The results suggest that the effects of secondary electron on sheath increase with increasing the applied voltage of conductor,and the secondary electron affects the characteristics of sheath by changing the surface potential of the insulator.