The invention relates to a composite biological 
trickling filter for 
denitrification and dephosphorization, belonging to the technical field of 
sewage treatment. The biological 
trickling filter is cylinder-shaped and comprises a water distributing area, a stuffing layer and a water catch area from top to down; wherein, the water distributing area comprises a plurality of rollers, a rotary water 
distributor, a water inlet 
pipe, a 
water pipe, a water 
sprayer and tracks; the water inlet 
pipe is connected with the rotary water 
distributor, the rotary water 
distributor is connected with the 
water pipe which is provided with a water outlet, the water 
sprayer is positioned below the 
water pipe and is connected with the rollers; five 
layers of grid frames are arranged vertically in the stuffing layer, and the grid frames separate the stuffing layer into a grid structure, so that the stuffing layer is successively separated from bottom to top into a stone and sand layer, a composite steel 
slag stuffing layer, a plaster stuffing layer, a 
sawdust stuffing layer and a 
coke layer; the water catch area comprises a header tank, a water outlet 
pipe and a water catch plate, wherein, the header tank is positioned at the bottom of the trickling filer, and the water outlet pipe is connected with the header tank. By introducing the grid frames, the composite biological 
trickling filter has the advantages of eliminating the problems of the filter blockage, water accumulation and other defects, effectively improving the 
aerobic bacteria processing performance of the composite biological trickling filter, efficiently removing COD and simultaneously achieving the effects of 
denitrification and dephosphorization.