Automatic metal detecting instrument

The invention discloses an automatic metal detecting instrument which comprises a machine frame, a conveying mechanism used for conveying a to-be-detected object, a detecting probe and an electric control device. The conveying mechanism and the detecting probe are supported on the machine frame; the detecting probe is a portal probe which comprises a portal frame and a group of opposite transmitting-receiving coils; the opposite transmitting-receiving coils are oppositely and respectively arranged in the opposite sides of the portal frame; a conveying belt is arranged penetrating through the portal frame; an MCU control chip arranged in the electric control device is used for controlling the signal transmission of the transmitting coils, signal receiving of the receiving coils and the running of the conveying mechanism. Therefore, the automatic metal detecting instrument realizes automatic data collection and improves the data detecting accuracy of specific metal substances in food and medicine.