The invention relates to an automatic pressure flush type rapid filter which comprises a bucket, characterized in that a clear
water discharge pipeline is arranged at the upper end of the bucket, a pre-filtering water pipeline and a
sludge discharge pipeline are respectively arranged at the lower end of the bucket, a filtering material layer is arranged in the bucket and comprises a plurality of filtering material elementary
layers arranged sequentially from the top down, and the filtering material elementary
layers can be sequentially reduced in hole
diameter from the bottom up according to particle diameters. In a flushing state, muddy water is filtered by
layers from the bottom up through a water inlet pipeline and the filtering material layer, filtered clear water is discharged from the clear
water discharge pipeline at the upper end, and
sludge deposits in a
sludge bucket and is discharged from the sludge
discharge pipeline; and in a back flushing state, water reversely flows downwards from a clear
water storage area to flush the filtering material layer by the self
gravitational potential energy, and accumulated sludge is discharged from the sludge
discharge pipeline below. The process is combined with a rapid
filtration self-solidifying process, back washing is performed by the self pressure of the liquid level of the water, and a back washing pump is saved, thus saving the cost and having good effects.