The invention discloses a multifunctional full-automatic potato combine harvester, and relates to the technical field of farm machines. The multifunctional full-automatic potato combine harvester comprises a steering traction mechanism, a machine head mechanism, a feeding shovel mechanism, a first seedling and potato conveying mechanism, a second seedling removing conveying mechanism, a third potato and stone conveying mechanism, a fourth lifting conveying mechanism, a fifth steering conveying mechanism, a sixth winnowing conveying mechanism, a winnowing mechanism, a stone conveying mechanism, a large-small separating mechanism, a seventh large stock bin feeding conveying mechanism, a large stock bin discharging conveying mechanism and a small stock bin discharging conveying mechanism. A main power source is supplied by a tractor. By means of the multifunctional full-automatic potato combine harvester, seedlings and potatoes can be separated automatically, so that labor intensity is greatly lowered, and human cost is reduced.