In order to enhance the interactive capability of the ‘internet of things’ automation system, a new human-computer interaction model is constructed using a speech input method and based on a four-layer architecture and input operation mode of a power automation system. A coding principle which can simplify speech input is proposed to tackle the difficulties of human-computer speech interaction of the model. Then with the new interactive model, scheme research is carried out. Finally, it verifies the application in the window system file object operation, window command execution and remote control and other ways. The verification results show that the application of the simplified speech coding automated interactive model could effectively improve human-computer interaction efficiency and promote the development of the power system. This work is supported by National Natural Science Foundation of China (No. 41601432).