Upon analyzing the input characteristics and different input tools for the HCI of EMS， the paper proposes to use speech recognition in the design of HCI input terminal. Input tasks are distributed to the speech recognition， mouse and keyboard in accordance to the characteristics of each tool. This forms a new input mode in term of command control， based on the coordination of mouse and speech. Compared with the conventional HCI， the method features higher operating efficiency， more freedom of input and better displaying quality of output. Experimental results demonstrate the advantages of the method.