A longitudinal metal plate loading/unloading and cutting method and a system thereof involve two longitudinally moving loading/unloading and cutting operation lines arranged in parallel, each of the operation lines comprising a block loading station, a cutting station, a sheet unloading station, and a carrying and stacking robot arranged between the two operation lines, which are arranged in succession, wherein the two operation lines have block loading directions opposite to each other; the block loading station and the sheet unloading station are respectively provided with a block cart and a sheet cart and guide rails; the cutting station is provided with at least two laser cutting heads and a moving quick table; the moving quick tables move longitudinally and allow feeding and discharging in two directions, and are each provided with two waiting stations and a cutting station; the external shaft of the carrying and stacking robot extends over the block loading station of the respective operation line and a
