The present invention relates to a method for protecting MU-MIMO (Multi User-Multiple Input Multiple Output) data through a multi-RTS/CTS frame exchange in a MU-MIMO based wireless communication system. The method of the present invention comprises: a process where an indicator for VHT data protection is added to an RTS frame, using the structure of an RTS/CTS frame for an existing legacy terminal during the multi RTS/CTS frame exchange; a process where an access point designates and then transmits the duration period of the RTS frame while transmitting the RTS frame; and a process where wireless terminals up to the (n−1)th terminal designate the duration period of the CTS frame as ‘0’ and send the designated duration period, while only the n-th wireless terminal designates NAV for data protection.