The invention provides a brain-computer interface based doctor-patient 
interaction method, which adopts a brain-computer interface based doctor-patient interaction 
system comprising an electroencephalographic collection module and an electroencephalographic analysis and doctor-patient interaction module. The method comprises the following steps of: setting visual stimulation signals with different frequencies, displaying the signals on a display, and mapping into controls of four commands through different combined codes (00, 01, 10 and 11) of 0 and 1; collecting an electroencephalographic 
signal of a subject by an 
electrode in real time, sending into a computer after the 
signal is amplified; analyzing the electroencephalographic 
signal; and 
broadcasting a voice prompt corresponding to the identification result through a speaker, and displaying the result on the display. Therefore, 
medical staff can carry out corresponding rescue according to the display and voice. The 
brain state can be identified by the brain-computer interface technology, and external equipment is accurately driven in time, so that communication and control can be realized. Brain can be effectively excited to generate 
steady state visual 
evoked potential by 
visual stimulations in different frequencies, the electroencephalographic signal can be accurately identified under stimulations in different frequencies through signal calculation and 
processing functions of the computer, and real doctor-patient interaction can be realized in the result display and voice prompt mode.