With the rapid development of high-energy-density battery technology, breakthroughs in in-situ high-precision internal stress detection technology will directly determine the potential for improving battery lifespan and safety. This paper systematically reviews the research progress in internal stress detection technology for batteries and its critical role in optimizing battery performance and enhancing safety. First, it analyzes the primary sources of internal stress in batteries, including electrochemical volume changes, thermal stress, and mechanical loads, and discusses their impact mechanisms on electrode material degradation, lithium dendrite growth, and cycle life decay. Next, it elaborates on current mainstream detection methods: direct measurement, indirect inference, and apparent parameter correlation, comparing the resolution, invasiveness, cost, and detection accuracy of each technique. Furthermore, practical applications of these technologies in lithium-ion batteries, solid-state batteries, and production line quality control are examined through case studies. Finally, a comparative analysis of the characteristics of different detection methods is provided, offering theoretical support and technical references for achieving rapid and accurate measurement of internal stress in batteries.