Disclosed is a device for preventing fire in a battery pack used a battery powered vehicle. In particular, a battery pack housing is installed and configured to cover the battery pack, and includes an inlet and an outlet to circulate air therein. A fire sensor is provided in the battery pack housing and detects/senses gas when a fire occurs in the battery pack. In response, a damper installed in each of the inlet and the outlet, is configured to selectively open or close the inlet and the outlet based upon signals from a controller that is configured to send opening signals or a closing signals to the damper depending on whether the fire sensor detects gas or not.