The invention provides a method for suppressing thermal runaway of lithium batteries, which is included a step of providing a lithium battery capable of performing charging and discharging, which includes an electrochemical reaction system. When the temperature of the lithium battery reaches to a predetermined temperature, a metal ion (A) and an amphoteric metal ion (B) are applied to the positive active material layer and the negative active material layer of the lithium battery to passivate the positive active material layer and the negative active material layer. The metal ion (A) is selected from a non-lithium alkali metal ion, an alkaline earth metal ion or a combination thereof to prevent the thermal runaway from occurring.