Abstract: An autonomous sound source search strategy composed of robot hearing and ultrasonic obstacle avoidance is proposed.According to the priority level,the search strategy is divided into three modules:source determination,ultrasonic obstacle avoidance,and sound source search.The current executing module is determined through the priority judgment. Sound source localization is realized based on improved localization method of time delay estimation.The robot searches and reaches the source with the ultrasonic obstacle avoidance method.The system is tested in room environment,and experiment results show that the robot is capable of localizing sound source in a reverberant environment,and approaching and confirming it without colliding obstacle.The method is proved efficient and practical enough for real-time operation.