Composite suspended bed denitrification filter tank equipment

The utility model discloses composite suspended bed denitrification filter tank equipment which comprises a denitrification filter tank body, and a water distribution area, an expansion gas distribution area, a secondary reaction area, a main reaction area and a clear water area which are sequentially distributed in the denitrification filter tank body from bottom to top, a water inlet pipe opening is formed in one side of the lower end of the water distribution area, and a water outlet pipe opening is formed in the other side of the lower end of the main reaction area; a cover plate is arranged at the upper end in the water distribution area, water passing holes are embedded in the cover plate, an air inlet pipe opening is formed in the outer wall of one side of the expansion air distribution area of the denitrification filter body, an air outlet is formed in the outer wall of the expansion air distribution area opposite to the air inlet pipe opening, and an air pipe grid is connected between the air inlet p