An uplink multi-user multi-input multi-output establishment method includes broadcasting, by a network side device, an uplink data sending announcement; receiving buffer information sent by a terminal that needs to send data, where the buffer information includes at least a sending level and a data sending length of to-be-sent data; determining, according to the buffer information, scheduling information for establishing uplink multi-user multi-input multi-output; and sending, to a terminal that is allowed to send data and selected from the terminal that needs to send data, a clear to send frame that carries the scheduling information, so that the terminal that is allowed to send data sends the to-be-sent data according to the scheduling information. The embodiments of the present disclosure effectively implement uplink multi-user multi-input multi-output establishment, so that signaling interworking is reduced, resource overheads are reduced, and data sending efficiency is improved.