Specific properties and working parameters of threshing and cleaning in two-stage harvesting for rapeseed in south China were explored. The optimal type of threshing and cleaning units, and two component reasonable working parameters were reached by orthogonal experiments of threshing and cleaning, which also offered reference for designing and using the rapeseed pickup-combine. Test results indicated: optimal parameter group of threshing separate smuggle loss rate were feed quantity,1.6kg/s; roller rotating speed, 750r/min; threshing interval, 15mm; and 6pole spike-tooth cylinder. Primary and secondary factors of threshing separate smuggle loss rate were cylinder type, feed quantity, threshing interval and roller rotating speed. The optimal parametric group of least cleaning loss rate and least impurity rate were scale sieve with opening 10mm; vibration sieve crank rotating speed, 260r/min; centrifugal blower rotating speed, 860r/min; centrifugal blower tilt angle, 15°. Primary and secondary factors by fuzzy analysis of synthesize evaluation were centrifugal blower tilt angle, vibration sieve crank rotating speed, vibration sieve type and centrifugal blower rotating.