Abstract: Both equivalence principle and superposition principle are adopted for discussing electrostatic equilibrium problem of series parallel conductor plates. The physical meanings about the mathematic resuhs are also studied. We have pointed out that plates can be divided into some classic and basic partitions according to the boundary condition; each partition can be solved very easily. The problem of this type can be transformed to very simple situation that only contains two plates by using integral method.

Key words: boundary condition, equivalence principle, superposition principle, integral method