Lithium-ion battery has attracted more and more attention under the background of energy crisis and environmental pollution, and safety issues have become the focus of attention. A new detection method is proposed in this paper to overcome the problems of poor versatility, low accuracy and poor sensitivity in aerosol and smoke detection in the early warning of lithium-ion battery failure. It is a photodetector based on Mie scattering theory, which can assist temperature, voltage and current data to realize online detection. The experiments have shown that a lithium-ion battery with a battery capacity of only 300 mA was overcharged under low power conditions. The aerosol and smoke generated by the battery failure and rupture were easily detected by the detector. A small amount of aerosol and smoke could be detected under overdischarge conditions, and the feasibility of the method was fully verified. The results show that on-line detection of lithium-ion battery failure can be achieved under extreme conditions with few nuisance alarms, and it is characterized by low cost, high speed, high efficiency and good universality.