Harvesting and storing energy is a key problem in some applications. Elastic energy storage technology has the advantages of wide-sources, simple structural principle, renewability, high effectiveness and environmental-friendliness. This paper elaborates the operational principles and technical properties and summarizes the applicability of elastic energy storage technology with spiral springs. Elastic energy storage using spiral spring can realize the balance between energy supply and demand in some applications. Continuous input–spontaneous output working style can provide simple energy sources for short-time energy supply, and provide strong moment impact and rapid start, or realize the energy conservation for reciprocating movement. Uniform output working style can realize energy output with uniform speed for timekeeping and load-driving. Random input working style can harvest and store random mechanical energy or convert small torque into a large moment to drive external loads. Finally, this paper proposes new researches and developments of elastic energy storage technology on new materials and structures, mechanical properties and structural dynamics analyses, design and control for new functions.