The human-machine engineering and interaction technology of high-speed EMU(Electric Multiple Units) can provide support for the design and verification of cab and compartment, which can improve the visibility, comfort, safety and tactility of the interior space. In the field of human machine interface (HMI) of high-speed EMUs, users also make higher requirements for comfort. Based on the original size of the seat chamber of the high-speed EMU, this method provides values according to the psychological correction questionnaire, uses the analytic hierarchy method to calculate the weight of different test participants, different functional parts and other factors, with the goal of improving the user's riding comfort, attaches the psychological correction amount to each functional area of the seat room, and performs simulation tests on RAMSIS software. According to the comfort score rule of RAMSIS, the results show that the addition of psychological correction to the size design of the interior facilities can reduce the overall discomfort of each carriage by 1.7, the discomfort of each body part by 2.6 and the spinal health index by 0.4.