Battery pack thermal runaway prediction method, device and system and power supply system

The invention belongs to the technical field of battery safety, and particularly relates to a battery pack thermal runaway prediction method, device and system and a power supply system. The method comprises the following steps: acquiring an expansion force detection signal output by a force sensor of the micro-electro-mechanical system; the expansion force detection signal comprises a battery pack detection signal and at least one battery cell detection signal; determining expansive force data in a housing of the battery pack based on the battery pack detection signal; based on the at least one battery cell detection signal, expansion force data in the shell of each battery cell is determined; and on the basis of the expansive force data in the shell of the battery pack and the expansive force data in the shell of each battery cell, predicting the risk of the thermal runaway fault of the battery pack. The risk of the thermal runaway fault of the battery pack is predicted based on the expansive force, and ear