Abstract: In terms of the magnetic characters of motor vehicles in single-driveway traffic system,it can obtain and deal with the information of motor vehicles’ flux and speed conveniently and quickly,via using the automatic detecting system based on micro-magnetic sensors.This paper puts forward a kind of automatic detecting system based on SOP（system on PCB） of micro-magnetic sensor,it can reliably finish the detecting of feeble magnetism signal,signal processing,and data memorizing.By experiment validating,it really realizes unmanned and intelligent manage of motor vehicles’ detecting in traffic system.