The utility model belongs to the technical field of filters, and particularly relates to a dust discharging one-way valve of a filter. The dust discharging one-way valve of the filter mainly solves the technical problem that the design is not reasonable in the prior art. The dust discharging one-way valve of the filter is arranged on a dust collector of the filter, and the dust discharging one-way valve comprises an upper valve body which is in the shape of a cylinder and a lower valve body which is in the shape of a tube. One end of the upper valve body is an air inlet end, and the other end of the upper valve body is an air outlet end. The inner end of the lower valve body is inserted into the air inlet end of the upper valve body, and the outer end of the lower valve body extends out of the upper valve body. The air inlet end of the upper valve body is provided with a one-way air intake mechanism enabling airflow to enter the upper valve body through the lower valve body, and the inner diameter of the upper valve body is greater than the inner diameter of the lower valve body. Compared with the prior art, the dust discharging one-way valve of the filter has the advantages of being more reasonable in design, simpler in structure, strong in dust discharging ability, and long in service life.