The utility model relates to a mechanical-electrical electric key, which comprises a keyboard. The utility model is characterized in that the keyboard 28 is has twenty keys composed of four rows and five columns; an emergency key 8 is arranged on the keyboard; the bottom surface is provided with a cushion corner 26; one side of the keyboard is orderly provided with a power switch 1, a voltage-stabilizing charging socket 2, a telefax input port 3; an electric key output / telefax output port 5, the button of a lock catch 6 and a polarity converting switch 7. The utility model avoids the insufficiency that the existing electronic key which is not favorable for blind sending with one hand has poor arranged regularity, high bit error rate and poor pressure resistance.