Due to the rapid development of the space industry, ever higher demands are being made for the optimization and improvement of spacecraft thermal management systems. Thermal control technology has become one of the key bottlenecks that restrict the level of spacecraft design. In this paper, the thermal management technologies (TMTs) for spacecraft electronics are reviewed according to the different heat transfer processes, including heat acquisition, heat transport, and heat rejection. The researches on efficient heat acquisition include the utilization of high thermal conductance materials, the development of novel package structure based on micro-/nano-electromechanical system (MEMS/NEMS) technologies, and advanced near-junction microfluidic cooling techniques. For the heat transport process, various heat pipes and mechanical pumped fluid loops (MPFLs) are widely implemented to transport heat from heat generation components to the ultimate heat sinks. The heat pipes are divided into two categories based on their structure layout, i.e., separated heat pipes and unseparated heat pipes. The merits and demerits of these heat pipes and MPFLs (including the single-phase MPFL and the two-phase MPFL) are discussed and summarized respectively. In terms of the heat rejection for spacecraft, thermal radiators are normally the sole option due to the unique space environment. To meet the requirements of large heat dissipation power and fluctuated thermal environment, research efforts on the radiators mainly focus on the development of deployable radiators, variable emissivity radiators, and the combination with other techniques. Due to the fluctuated characteristics of the heat power of internal electronics and the outer thermal environment, the phase change materials (PCMs) exhibit great advantages in this scenario and have attracted a lot of research attention. This review aims to serve as a reference guide for the development of thermal management system in the future spacecraft.