Abstract: In order to study the large volume lithium ion battery in the flameproof enclosure applied to the coal mine weather or not would cause a deflagration and pressure released of the battery, cause the battery explosion to make a gas secondary explosion, cause the gas explosion to make the secondary battery explosion and other accident as well as the pressure occurred from the accident weather or not would be over the design allowance of the flameproof enclosure, the paper analyzed causes of accident occurred and had a study on accident with simulation tests of battery short circuit, overcharging, gas explosion and others. The study results showed that the short circuit of battery would not cause accident occurred, but would cause the failure in the battery. The battery overcharging would cause the battery explosion and pressure released and the pressure could be over allowance of flameproof enclosure design. The gas explosion occurred in the flameproof enclosure would not occur an accident and would not be affected to the normal application of the battery.