The invention relates to a method for detecting the brake pressure state of a train vehicle, which comprises the following steps of: obtaining and storing the current pressure value inside a brake cylinder; obtaining the current pressure voltage inside the brake cylinder after delaying for a first set time period; calculating the two pressure values to obtain the current pressure change rate of the brake cylinder; obtaining the pressure state of the brake cylinder through the current pressure change rate, and comparing the obtained pressure state with the former pressure state of the brake cylinder; if the two pressure states are the same, storing the pressure state of the brake cylinder, and discarding the obtained current pressure value; and if not, executing the step of storing the pressure state of the brake cylinder and storing the obtained current pressure value. The invention also relates to a device for realizing the method. With the method and device for detecting the brake pressure state of a train vehicle provided by the invention, the pressure state inside the brake cylinder can be obtained in real time, and the efficiency is high.