The invention provides a keyboard input method of a control system display control terminal. According to the method, small keyboard physical keys, user function interface soft keys of the display control terminal and a mapping module are included, and the method comprises the steps that when the small keyboard physical keys are pressed, a key-pressing event is triggered, when the key trigger time at two times is longer than 300ms, the mapping module reads tab information of a main interface, the pressed key value code is scanned, the soft keys corresponding to the pressed key value are analyzed through the mapping module, the key attribute is changed to be true from acquiescent false, a static value change event is triggered, and the corresponding function trigger is achieved. The keyboard input method has the advantages that the defect that due to the facts that the space size is restrained, and the number of the small keyboard physical keys is limited, the multifunctional operation requirement of a user for the control system display control terminal cannot be met is overcome, reuse and expanding of the small keyboard physical keys is achieved, and the real-time man-machine interaction of a complex control system is completed.