Faml-4 is desgined for the Middle scale underground mine. The performance of traction is improved lot and the tire wear is reduced because of using the advanced NO-SPIN differential at the rear axle and POSI-TORQ differential at the front axle, which can differ not only in the speed, but also in the torque. It is safe and reliable for brake, then prolong service life without maintenance because of SAHR( POSI-STOP )brake; The shift gear is friendly opearted and the efficiency becomes higher by mean of electronic controlling shift. We make use fo the signle circuit hydraulic system to assure the service system reliable. The structure becomes more compact owing to using 4 links Hoist-Dump service configuration.