Spinal cord injury (SCI) triggers complex inflammatory and pathological processes that ultimately lead to scar formation, thus resulting in the severe and irreversible loss of function. The composition of spinal cord scars in SCI can be divided into cellular components and non-cellular components such as the extracellular matrix (ECM). Studies targeting the ECM, such as chondroitin sulfate proteoglycans (CSPGs), have achieved promising therapeutic results. On the other hand, with the application of new techniques in the field of SCI, an increasing body of research has been targeted to the complex mechanisms that occur in the cellular components during scar formation. Here, we meticulously describe the spatial distribution and dynamic changes of the cellular components involved in the formation of scars following SCI, including microglia, astrocytes, fibroblasts, and macrophages, paying particular attention to the recent application of new technologies. In addition, we outline the therapeutic approaches that target the cellular components of scar formation and explore potential therapeutic measures to improve functional recovery after SCI.