In order to satisfy the low speed requirement of wind power generation system, two different types of axial flux permanent magnet machines were designed in this paper. The paper analyzed the different characteristics of these two kinds of topological structure, the shape of the permanent magnet poles and polearc coefficients were determined, the generators of slotpole coordination problem was discussed, and the parameters of the permanent magnets and windings were calculated in detail in this paper. The paper computed the models with the quasi3D finite element analysis (FEA) methodology for both generators, the reliability of designed methodology applied in axial flux permanent magnet machine was proved by finite element analysis (FEA) results. At last, the electromagnetic characteristics of these two types of generators were compared by Finite Element Analysis (FEA) results.