The deep-sea contains an abundant of natural resources and treasures that still remain unrecognized and unexploited. To obtain these resources, developing advanced submersibles that are able to explore the deep-sea becomes a challenge. In the extreme harsh environment such as ultra-high pressure and low temperature in the deep sea, the advanced deep-sea submersibles have to be reliable and stable. In this regard, a power supply system is extremely important for the deep-sea submersibles because its performance directly affects the operation capability, safety and reliability of the deep-sea submersible. Therefore, recent efforts have been devoted to the development of deep-sea power sources. The existing deep-sea power systems have experienced the development stages of lead-acid batteries, silver-zinc batteries, lithium-ion batteries, and high-energy-density solid-state lithium batteries. This review elaborated the main classification of deep-sea power sources. In addition, the challenges and future development trends of batteries for deep-sea submersibles were also discussed. It is expected that this review could provide a reference for the further development of the power supply systems for more reliable and advanced deep-sea submersibles.