Abstract: Aimed at the low working efficiency of more domestically used model 4YW-2 corn harvester and poor adaptability in operation of incorrect line etc, in the original models based on the harvesting machine header, ear forwarder and power transmission components were improved. A field experiment was conducted to show that improved models for operation of incorrect line from corn planting improved adaptability, at the same time, reducing the ear-corn loss rate, the rate of loss of grain and grain crusher rate, which provided references for the mechanical design of the corn harvester of incorrect line.