Combined step perforated screen for maize harvester

The utility model provides a combined step perforated screen for a maize harvester. The combined step perforated screen comprises a detachable step perforated screen body and a fixed step perforated screen body. The detachable step perforated screen body is installed on the fixed step perforated screen body through a bolt and then is fixed through a frame. The detachable step perforated screen body is transversely provided with at least one detachable straw shaking plate and detachable step screen pieces. The fixed step perforated screen body is transversely provided with at least one fixed straw shaking plate and fixed step screen pieces. Handles are arranged at the tail end of the frame. Maize kernel holes are formed in the detachable step perforated screen body and the fixed step perforated screen body. According to the method that the original screen pieces of a lower screen are replaced by the detachable step screen pieces, the air volume of an upper screen can be adjusted, and adaptability is improved; due to the fact that the detachable step perforated screen body is connected to the fixed step perforated screen body through the bolt, the detachable step screen pieces can be optionally installed according to practical situations, and therefore the appropriate air volume can be selected. The combined step perforated screen is simple in structure, low in cost, convenient to disassemble and assemble, practical and reliable.