A method for detecting an available bandwidth based on a burstiness of a key frame of a video stream, includes: establishing a video connection between a sender and a receiver, and sending the video stream by the sender to the receiver; recording a sending timestamp of each packet at the sender; recording a receiving timestamp of each packet received by the receiver; calculating a difference between the receiving timestamp and the sending timestamp of each packet, and obtaining the packet with the smallest difference and the packet with the greatest difference by traversing the packets in the key frame; and estimating a currently available bandwidth according to the packet with the smallest difference and the packet with the greatest difference.