To evaluate the applicability of lithium-titanate oxide (LTO) battery in pulsed high power laser system (PHPLS), this paper summarizes the requirements of the PHPLS for the primary energy storage device based on the discharge capacity and safety application characteristics of the energy storage medium, analyzes the applicability of the common energy storage medium through analogy and theoretical calculation, and verifies the engineering application feasibility of LTO by discharge performance test and safety test. The results show that the LTO has high discharge capacity and high safety, which can meet the application requirements of the PHPLS, and has the conditions for promotion.