Precise cellular analysis is one of the core goals in contemporary life science research. As a key prerequisite for achieving this goal, single-cell encapsulation effectively isolates individual cells from complex cell populations. Microfluidic technology, by precisely manipulating microscale flow dynamics, provides robust technical support for efficient and controllable single-cell isolation or encapsulation. From the perspective of microscale flow, this work systematically reviews microfluidic technologies for single-cell encapsulation, focusing on flow mechanisms, technological evolution, and performance regulation strategies for encapsulation methods and for enhancing encapsulation efficiency. Single-cell encapsulation achieves cell capture and encapsulation through hydrodynamic effects such as low-Reynolds-number flow and interface instability, while encapsulation enhancement technologies overcome the limitations of conventional encapsulation efficiency by regulating processes like cell separation and focusing, thereby enabling efficient cell encapsulation. Understanding flow mechanisms helps improve encapsulation performance. By elucidating flow mechanisms to enhance encapsulation efficacy, this study collates hydrodynamic distinctions across methodologies, articulates their cardinal advantages and inherent limitations, furnishes theoretical guidance for mechanistic research and experimental design in single-cell encapsulation, and fosters deeper integration of microfluidic approaches within biofluid mechanics.