Abstract: Aiming at the problems of severe equipment loss, reduced yield rate and impaired rolling stability caused by edge cracking during the cold rolling process of high-strength steel for carriage application, the causes of edge cracking were analyzed by means of scanning electron microscope(SEM), microhardness tester, thermal dilatation phase transformation tester and other instruments. The results show that the microstructure at the edge of the cold-rolled strip consists of super-cooled M-A constituents and ferrite. Due to the mismatch in cold plastic deformation capacity between M-A constituents and the surrounding ferrite matrix, interphase cracking is prone to occur at their interface, which develops into edge cracking defects under high-tension rolling. To address this issue, a series of process improvement measures were proposed: controlling the finishing rolling temperature above 900 ℃; activating the edge shielding function during the laminar cooling process; raising the coiling temperature to 750 ℃ and adopting the U-type coiling process, with laminar cooling water not applied to the head and tail of the strip to maximize the coiling temperature of these parts; stipulating that the temperature of hot coils entering the slow cooling pit should be not less than 600 ℃ after discharge. These measures can promote the formation of ferrite + pearlite microstructure at the strip edge. In addition, the cold rolling total reduction was optimally controlled at 45%-50%, and the setting values of tension and bending roll force were adjusted. Through the above comprehensive measures, the occurrence of edge cracking defects was reduced to less than 1%.