The utility model relates to a sump pit precipitation anti -pollution device, include: frame construction includes: through upper ledge, center and the lower frame that vertical rod laid, the center is equipped with the support bracket who supplies to place the suction pump, connect in vertical rod and enclose the protection network of locating frame construction, and lay in the filter screen of lower frame bottom. The utility model discloses sump pit precipitation anti -pollution device passes through the frame cage that frame construction, protection network and filter screen overlap joint become the bottom lock for place the suction pump, guarantee the bottom mud distance within a definite time of suction pump and soft soil area deep basal pit, thereby reduce the risk of blocking up of suction pump.