The invention discloses a device for raising information display reliability of a man-machine interaction unit and a method thereof. A communication module receives train control and state information sent by a vehicle-mounted host, and a first processing module calls an interface function in a graphic library based on the received information and generates graphic drafting data in a memory. The first processing module transmits the information from the vehicle-mounted host to a second processing module, and the second processing module calls the interface function and generates graphic drafting data in the memory. After the graphic drafting data of the second treatment module is generated, the first processing module consistently compares the self graphic drafting data with the graphic drafting data of the second processing module to determine display of the graphic drafting data or the or close the backlight of the man-machine interaction unit. The method and the device overcome the technology problem that the man-machine interaction unit displays error information in a train operation process to cause liability disputes or on-site accident because of maloperation or inoperation of a driver, raise reliability of the display information, and guarantee drive safety.