The invention provides an etching process of a magnesium alloy etching plate. The etching process comprises the steps of plate burning, plate opening, acid pickling, etching, drying and the like. Whena relief printing plate or a gravure plate is manufactured through etching, the process parameters of etching comprise the rotating speed, the etching liquid temperature, the etching time and acid adding. For a specified etching machine, etching liquid is prepared according to a certain proportion, high-efficiency and high-quality etching of a magnesium alloy etching plate is achieved through real-time temperature control and timely acid adding, and after the magnesium alloy etching plate is made according to the process, the gradient is proper, and the edge is sharp; and after gold stamping,the surface of a printed material is clear and smooth.