This book highlights the theory and application of Magnetorheological Finishing (MRF) technology in the fabrication of high-precision optical components, and provides a comprehensive framework covering its underlying theory, core technologies, and engineering practice. Aligned with the title Magnetorheological Finishing Theory and Key Technology of Optical Components, it integrates the fundamental principles of MRF with the manufacturing requirements of off-axis aspheric optical components, offering an innovative solution to the long-standing challenges in conventional optical processing. The methodology detailed herein not only demonstrates the irreplaceable role of MRF in modern optical manufacturing, but also showcases its unique strengths in enhancing the fabrication accuracy and surface quality of optical components. This book consists of two main parts: the first elaborates on the fundamental theory and key processes of MRF, while the second focuses on the key MRF technologies tailored for off-axis aspheric optical components. Its content spans the development history of MRF, basic principles, process parameter optimization, experimental research, and engineering case studies, with the aim of providing readers with systematic, end-to-end guidance from theoretical fundamentals to practical implementation. This book is intended for researchers and engineering designers in the fields of mechanical engineering and optical engineering, as well as practitioners engaged in the manufacturing of high-precision optical components.