This paper introduces the process design of twin-roll casting production line of wide magnesium alloy sheets in detail from three aspects of process flow,process equipment and main process parameters,analyzes the influence of different process parameters on the casting and rolling process,and provides guiding parameters for twin-roll casting.The success of wide magnesium alloy coil by twin-roll casting has realized the wide and large-scale production of magnesium alloy strip,and promoted the rapid development of magnesium alloy industry.