The invention discloses a defoaming method during dewatering of a washing machine and a dewatering method of the washing machine. The defoaming method during dewatering of the washing machine comprises the following steps: S1, spraying water into a dewatering barrel by virtue of a spraying device, and enabling the dewatering barrel to rotate at a first preset speed v1, enabling the dewatering barrel to stop rotation after rotating at the first preset speed v1 for a first preset time t1, closing the spraying device and discharging water; S2, after dewatering, and enabling the dewatering barrel to rotate for dewatering at a second preset speed v2 for a second preset time t2, wherein the first preset speed v1 is less than the second preset speed v2. According to the defoaming method during dewatering of the washing machine, the spraying device is additionally arranged on the washing machine, sprayed waterflow can disperse foam, and then foam is removed, so that the resistance during a dewatering process is reduced, the dewatering barrel is enabled to rotate at a high speed, temperature increase of a motor is reduced, the service life of the motor is prolonged, energy consumption is reduced, and thus the problem that the dewatering barrel is incapable of rotating at a high speed due to multiple foams in a dewatering process of the washing machine in the related art is solved.