The invention belongs to the field of washing machines, in particular to a washing machine and a control method. The washing machine comprises an outer cylinder, a particle collecting device and a power device, wherein a collecting cavity communicated with the outer cylinder is formed in the particle collecting device; and the power device is communicated with the collecting cavity/outer cylinder,and the power device drives a medium to carry cleaning particles in the outer cylinder into the collecting cavity for self-cleaning. The washing machine has the advantages that by arranging the particle collecting device and the power device, the power device drives the medium to carry the cleaning particles in the outer cylinder into the collecting cavity for self-cleaning, so that the cleaningparticles are collected by the particle collecting device while the cleaning particles are used for self-cleaning, the cleaning efficiency is improved, and the cleaning is carried out by collision andfriction between the cleaning particles and dirt/mold, so that the cleaning force is large, and the cleaning effect is good.