Embodiments of the present invention provide a buffer state estimation method and device. The method includes: obtaining a first continuous play duration corresponding to media data received by a terminal in a period of the present state estimation; calculating a second continuous play duration corresponding to media data in a current buffer according to a buffer state before the present state estimation and the first continuous play duration; and performing state estimation on the buffer according to the buffer state before the present state estimation, preset buffer configuration parameters and the second continuous play duration, and obtaining the present buffer state and start time and duration of the present buffer state, where the buffer state includes at least one of an initial buffering state, a normal play state, a rebuffering state, a play stop state and a play pause state.