The twenty-first century is facing a major issue of energy crisis，the country and enterprises urgently need to upgrade the energy structure and transform the energy mode． Gravity energy storage method is an important type of mechanical energy storage method，which is a clean energy storage method that converts gravitational potential energy into electrical energy and stores the electrical energy． A small gravity energy storage device was homemade in the laboratory，and the structure of various parts of the traditional device was optimized for equipment improvement．The effect of heavy mass，rise height and other unknown conditions on the efficiency of electrical energy conversion was investigated using a gravity energy storage device，which has the advantages of reducing experimental costs，saving time and facilitating multiple measurements compared to large gravity energy storage devices．In addition，because of the detachable and portable features of this device，it can also be used for teaching demonstrations and popular science displays．