WWS-1 type digital-double astatic magnetometers are being produced in batches by Beijing Geological Instruments Factory. By adopting double-astatic magnetic system, the diamagnetic capacity of the instrument is raised; a negative feedback system is employed, and a 31/2-digit voltmeter is used to measure magnetic intensity directly, whereby one might read the data rapidly. The instrument shows great stability and reliability in function, with its readings comparable with the magnetic parameters obtained by the same sort of instruments abrcad. The instrument can be employed in high-precision magnetic measurement of rocks and paleomagnetic measurement of samples.