The invention discloses a melt conveying flow balance compensation method and a stabilizing device for an eccentric rotor extruder. The method includes the steps that an eccentric rotor is divided into a fusion plasticizing section and a flow balancing section, and the eccentric distance of the flow balancing section is larger than the eccentric distance of the fusion plasticizing section, so thattwo chambers at the flow balancing section are communicated through a gap; when the pressure of one of the chambers is increased, part of a molten material flows to the other chamber through the gapunder the action of the pressure, and therefore flow balance compensation is realized. In the stabilizing device, the eccentric distance of the flow balancing section on the eccentric rotor is largerthan the eccentric distance of the fusion plasticizing section; in the fusion plasticizing section, the diameter of the eccentric rotor is equal to the short intercept of an inner cavity of a stator;and in the flow balancing section, the diameter of the eccentric rotor is smaller than the short intercept of the inner cavity of the stator. The problems of flow fluctuation and unbalanced extrusionflow of the eccentric rotor extruder are effectively solved, so that the melt extrusion is stable, the surface uniformity and dimensional stability of a product can be improved, and the product quality can be improved.