The invention discloses a method for automatically testing a DCS (Digital Control System) control cabinet, relating to the field of automatic control. A display module, an operation module, a control module and a conditioning module are included, wherein the display module is used for displaying various kinds of information of the operation module and the control module; the operation module is used for inputting various test commands to the control module; after receiving the test commands of the control module, the control module calls a corresponding test program to execute, transmits a generated test signal to the conditioning module, is responsible for receiving feedback information of the conditioning module, and outputs the result on the display module; and the conditioning module is used for conditioning the test signal transmitted by the control module and transmitting the conditioned test signal to a corresponding IO (Input Output) terminal in the DCS control cabinet, receiving a feedback signal of the IO terminal, and transmitting the conditioned feedback signal to the control module. By adopting the scheme, the testing state and an expected result can be reflected in real time, a control loop of a process system can be simulated through linkage of a plurality of test programs, a specific testing function can be realized, the testing efficiency is improved, and human resources are saved.