Abstract: In order to improve straw ensilage efficiency, reduce straw ensilage working links and manual consumption, authors developed 4YQK-2 combine harvester for corn and straw ensilage by optimizing the combination and improving the design of the working units based on existing corn harvest and straw ensilage mechanization technologies. The combine harvester was mainly composed of harvest header for corn and straw, straw blower, baling unit and automatic control system on feed stock and rope-send. It was able to harvest corn ear, meanwhile, the stems were collected, shredded, conveyed and baled, so the aim of function integration and phase coupling were achieved. Harvester for corn and straw utilized vertical cutters to shred stems and throw straw which could be transported by two-stage screw conveyors. Its structure was simple. Automatic control system on feed stock and rope-send adopted electromechanical integration technology to actualize the process control of feeding straw and sending rope. Experiments showed that the combine harvester was able to work safely and reliably, and had perfect effect of shredding, breaking and bundling for stems. It can meet the technical requirements of straw ensilage.