The invention provides a method and a device for detecting the switching value of a pressure switch. The device comprises a pressure generator communicated with a pressure switch through a pressure pipe, a pressure control element, a pressure sensor, and a controller provided with a data processing unit, wherein the pressure sensor is installed on the pressure pipe and electrically connected with the controller, the pressure control element is electrically connected with the pressure generator to control the pressure generator, and the pressure control element is electrically connected with the controller. According to the invention, pressure change of the pressure pipe is transmitted via the pressure sensor to the controller in real time, the data processing unit arranged in the controller acquires the pressure change value and generates a control instruction according to preset change rules of pressure, and the pressure generator changes the pressure in the pipe under control of the pressure control element. By adopting the device and the method provided by the invention, the switching value of a pressure switch can be detected, quick detection is realized, the accuracy of detection is improved, the repeatability of detection results is good, the labor cost is reduced, and work is reliable.