Filtering tank with double-layer filtering function

The utility model provides a filtering tank with a double-layer filtering function. The filtering tank comprises a filtering tank body and a double-layer filtering assembly mounted in the filtering tank body, the double-layer filtering assembly comprises an upper-layer filtering assembly and a lower-layer filtering assembly, the upper-layer filtering assembly is located above the lower-layer filtering assembly, and each of the upper-layer filtering assembly and the lower-layer filtering assembly comprises a plurality of filtering bags; the number of the filter bags of the upper-layer filter assembly is greater than that of the lower-layer filter bags for graded filtration. According to the double-layer filtering tank disclosed by the utility model, tail gas generated by the vacuum chemical vapor deposition furnace is filtered through the lower-layer filtering bag and the upper-layer filtering bag, so that the filtering effect is enhanced, the filtering bags are convenient to replace, the working process requi