System and Method for injecting a deicing agent in a muffler for a fuel cell electric vehicle

A fuel cell electric vehicle includes a muffler deicing agent injection system composed of a deicing agent injector injecting a deicing agent, which is pumped by a deicing agent injection pump, from a deicing agent tank and is supplied to a deicing agent pipe. The muffler deicing agent injection system performs a muffler deicing agent injection logic to inject the deicing agent through operations of the deicing agent injection pump and the deicing agent injector by a controller under an ambient temperature satisfaction condition and a deicing agent injection satisfaction condition.