A hooking-type fully automatic electric meter with a function of fully automatic detecting and choosing a measuring mode among the electric current, voltage and resistance measuring modes. A user only needs to turn on the electric power of the electric meter without performing any other procedures; he can get an accurate reading of the volume of electricity on the display screen. The meter is different from the manually selected clamping type meters with different functional positions for measuring the values of electric current, voltage and resistance. With the meter, damage to the main body of the electric meter in operating electric measuring and to the safety of the user himself can be avoided. This can significantly raise the industrial safety in measuring large volume of electric current, and can save actions and time for operating the electric meter, and convenience and efficiency in operating can be increased.