Micro-milling as a precision manufacturing process has received increasing attention for its unique advantages in machining tiny parts. The surface quality of parts is an important factor that affects the performance and life of micro parts. Therefore, the study of the surface quality of parts after micro-milling has become an important topic of great interest. In this paper, the surface roughness generation models are reviewed to provide a comprehensive understanding of the various factors affecting surface quality. Based on these models, the key factors affecting surface roughness and burr generation are summarized. Furthermore, the challenges and opportunities for achieving high surface quality parts during micro-milling are summarized and some suggestions for future research are expected.