Automatic strain feeding system for sewage treatment and strain storage tank with improved structure

The utility model relates to an automatic strain feeding system for sewage treatment and a strain storage tank with an improved structure, and belongs to the technical field of sewage treatment. The strain storage tank comprises a tank body and a three-way control valve fixedly arranged on a bottom plate of the tank body, the three-way control valve comprises a barrel and a valve element assembly, wherein the valve element assembly comprises a columnar valve body sealing piece; the cylinder body is provided with an in-cavity cylinder part and an out-cavity cylinder part; the upper end opening of the in-cavity cylinder part is sealed, and the in-cavity cylinder part is formed by adjacently connecting a non-hole cylinder part, a sieve hole cylinder part and a discharge hole cylinder part which are sequentially arranged from top to bottom; a water outlet outer connecting opening is formed in the side wall of the cavity outer cylinder part; the columnar valve body is of a barrel structure with an opening in the u