An obstacle avoidance device for detecting surroundings of an unmanned mobile device is disclosed, which includes a stabilization platform connected with the unmanned mobile device, wherein the stabilization platform includes a stabilizer for ensuring stably bearing at least one platform camera; and an obstacle avoidance module fixed with the stabilization platform, so as to reduce interferences to detecting the surroundings by the obstacle avoidance module when the unmanned mobile device acts. The obstacle avoidance device of the present invention is able to keep a stable attitude while the unmanned mobile device is unstable and changes an attitude thereof, so as to effectively avoid obstacles.