This book presents the design optimization method for switched reluctance motors (SRMs) and drive systems. It covers an in-depth literature review on the status and potential trend of design optimization techniques for SRMs, including design theory, modeling methods, topologies, control methods, and techniques for optimization efficiency and effects. Readers will discover new design methods based on the specific nonlinear characteristics of SRMs, and multi-objective optimization methods for the design of high-quality switched reluctance drive systems without or with the consideration of uncertainties, i.e., the deterministic and robust approaches. Multi-mode design optimization method regarding SRMs is investigated and some examples are presented. In addition, some essential trends in design optimization development are presented and highlighted as future perspectives. This book benefits students, researchers, engineers, and companies in the field of electrical drive design and manufacturing. The focuses of this book are different from those of the published books. The advanced optimization methods including deterministic optimization, robust optimization, and system-level optimization are not discussed in these books. Besides, new design method based on the nonlinear characteristic and multi-mode optimization combined with specific application will be introduced to the design of high-performance of switched reluctance machines.