The invention discloses a cotton collecting and cleaning conveyor of a cotton picker, and a cotton harvesting machinery composed of the conveyor; the cotton collecting and cleaning conveyor is mainlycomposed of a fan and a cotton cleaning mechanism; the fan comprises a transmission mechanism and a drive shaft; the drive shaft is provided with two groups of fan blades; a partition board is arranged between the two groups of fan blades; at the same time, separate fan shells for the two groups of fan blades are also arranged to form a main fan and an auxiliary fan; the cotton harvesting machinery comprises a cotton picking assembly and a cotton collecting box for storing the picked cotton; and the cotton harvesting machinery is also provided with the cotton collecting and cleaning conveyor.Compared with the prior art, the invention is simple in structure and only uses a fan to combine with a cleaning mechanism so as to complete cotton collecting, conveying, cleaning and conveying of thecotton harvesting machinery; besides, the invention has less power consumption and better conveying effect, which particularly can simplify the structure and reduce the power consumption to a greaterextent after being applied to a cotton picking machinery.