Method and device for detecting thermal runaway of battery pack

A method for detecting thermal runaway of a battery pack including a battery module in a master battery management system, the method comprising detecting a communication error with a slave battery management system that detects information on the battery module, if the communication error with the slave battery management system is detected, obtaining temperature of a master board from a temperature sensor located on the master board in which the master battery management system is installed, and detecting thermal runaway of the battery pack using the temperature of the master board.