Disclosed herein are an apparatus and method for detecting a malicious device based on swarm intelligence. The method includes detecting a malicious device by causing at least one exploration ant to access a device swarm along movement routes in which pheromone trail values are taken into consideration, wherein the exploration ant is generated in response to a detection request received from a security management server, when the at least one exploration ant detects a suspicious device that is suspected to be a malicious device, causing the exploration ant to return along the movement routes in reverse order, and returning pheromone trail values generated by devices on the return movement routes to a malicious device detection apparatus, and identifying whether the suspicious device is the malicious device by calculating an optimal solution based on a local information set generated by aggregating the pheromone trail values returned for movement routes.