The present invention discloses a suspended ceiling filtration apparatus, which includes filtration units. The filtration unit includes a filtration part, two horizontal strip support legs and two longitudinal strip support legs. A support plate protrudes from the support legs. The filtration part is placed on the support plate, and a buffer filling part is disposed between the filtration part and the support plate. The buffer filling part is utilized to self-adaptively swell and shrink relative to the support plate according to a weight of the supported filtration part, the buffer filling part fills a gap between the support plate and the filtration part.