Abstract: China is a big country of cotton production and consumption.However，in the process of cotton planting，labor in harvest link is very strong and operation is very difficult.Mechanized cotton picking plays an important role in liberating labor force，improving labor productivity，reducing production costs and increasing income of cotton farmers.Technical characteristics and application adjustment of key components of 4MZ-3A self-propelled cotton picker were introduced based on analysis of research status of self-propelled cotton picker at home and abroad.It provided reference for research and development of domestic self-propelled cotton picker.