针对我国北方小麦玉米一年两熟种植地区玉米收获时含水率高的特点及我国目前农村土地经营规模及发展趋势，设计了４ＹＦ－３、４Ｙ－３型两种自走式玉米联合收获机，这两种机型均可同时进行摘穗、果穗输送、果穗集箱、秸秆粉碎直接还田等多项作业，较好地解决了高含水率玉米果穗的收获和秸秆处理问题。生产率０．５～０．９ｈｍ２／ｈ，配套动力７８．７ｋＷ。 Aiming at the characteristics of high moisture content of maize harvested in the two-year-old wheat growing areas in the north of our country and the current scale and development trend of rural land in our country, two self-propelled corn combine harvesters of 4YF-3,4Y-3 were designed. Both of these two models can simultaneously carry out a number of operations, such as picking ears, transferring ears, delivering ears, setting straw, and returning straw directly to the fields, which can well solve the problem of harvesting corn ears and treating straw with high water content. Productivity 0.5 ~ 0.9hm2 / h, supporting power 78.7kW.