The invention discloses a hydrophobic type floating filter material filtering tank. The tank comprises a tank body, a filter material feeding valve pipe, a filtrate collecting tank, a water collecting valve pipe, a solid filter material sieve plate, a steady flow sloping plate, a filter material layer, a water distributing hole plate, a blow-down valve pipe and a liquid material feeding valve pipe, wherein a filter material in the filter material layer is hydrophobic foamed plastic beads. A hydrophobic type floating filter material adopts the hydrophobic type foamed plastic beads as filtering media, has the porosity being 90% or above and floats on the water surface because foam plastic is lighter. Besides, the filter material sieve plate provided with a stainless steel screen is used for downwards pressing the floating filter material and fixing the floating filter material under the water surface, so that a centrifugal liquid is filtered from bottom to top, the filtering tank has the characteristics of high filter layer contamination load, long operation cycle and high filtering speed; secondarily, the hydrophobic type filter material is not hydrophilic and is not incompatible with insoluble substances, and adsorption and filtration are performed by the aid of floc gradually formed among particles.