In this thesis, a flux switching permanent magnet generator (FSPMG) with three-stages skewing rotor applying in micro-scale hydropower generator was proposed. This innovation structure was arranged with a new type rotor called rotor skewing, which can reduce the cogging torque. Based on the inner holes design at rotor, there has six combinations of skewing angle in one rotor. The coil and magnets of FSPMG are located at the same side of outside stator. This arrangement was able to increase the speed adaptability of generator, which resolve the disadvantages of conventional generator only suitable for high speed. In research process, an Insert-mounted permanent magnet generator (IPMG) was used to compare the measurement and simulation results and established the appropriateness between the mathematical models and the actual structures. Then the flux density of magnet and the specification of FSPMG are derived by the method of equivalent magnetic circuit analysis. The dimension is limited at the diameter 12 cm of outer stator and the length 10 cm of stack length. The combination of stator slots and rotor poles are chosen for 12 and 10. The rated speed and the rated power of generator are 1200 rpm and 1 kW. A two-dimensional electromagnetic software ANSYS Maxwell was used to simulate the output performance of FSPMG structure such as flux density, back-EMF, harmonic distortion, core loss, strand loss, cogging torque and the output power in different rotor poles. The simulation results show that the structure of rotor tooth was optimized. At last, one set of FSPMG structure with 12 stator slots and 11 rotor poles are chosen for manufacturing the prototype. The experiment results show that the error of IPMG between the measurement and simulation can reach 2.6%, which confirms the accuracy of the numerical analysis. The simulation results show that the FSPMG can produce 1.1 kW with 6.9 Ω at 1200 rpm. Final, the prototype of FSPMG was measured with open-load test and loaded test with 6.9 Ω, the results are 75.6 V and 991 W. The error between simulation and measurement is 11.5% and 7.1%. The cogging torque measurement was measured in three skewing angle rotors: no skewing, equal difference skewing angle and equal ratio skewing angle. The results show that the cogging torque were 2.13 Nm, 0.85 Nm and 0.55 Nm, which decreased 60% and 74.2% respectively. It is confirmed that the skewing rotor can effectively reduce the cogging torque. This study provides a design and optimization process for FSPMG with a lower cost and high efficiency mathematical simulation analysis, and the skewing rotor effectively reduce the cogging torque and the torque ripple. Advisors/Committee Members: Chang Tang Pan (committee member), Zong Hsin Liu (chair), Jao Hwa Kuang (chair), Yong Jheng Chen (chair), Chung Kun Yen (chair).