Disclosed are a method and a system for processing a computer-generated hologram (CGH). The system for processing a CGH includes a CGH generation apparatus and a display apparatus. The CGH generation apparatus repeatedly performs a process of propagating object data from a first depth layer to a second depth layer, changing amplitude data of the object data to second predefined amplitude data, back-propagating the object data from the second depth layer to the first depth layer, and changing the amplitude data of the object data to first predefined amplitude data, and generates a CGH by using the object data.