Disclosed is a 
tower earthworm bio-
filter system, which is composed of a 
hydrolysis acidification tank and a multi-stage 
tower earthworm bio-filter. The 
hydrolysis acidification tank is a buried tank, the 
tower earthworm bio-filter employs 
modes of a 
modular structure, a gradient tower layer design and multistage units in series connection, and tower 
layers employ mode combination of a stair type or a rotary type. Inner water distributors are additionally arranged inside an earthworm 
bed for uniformly distributing water. The drop-
aeration technique and the 
water spray technique are employed to increase the concentration of dissolved 
oxygen in 
sewage. The tower earthworm bio-
filter system can effectively increase 
impact load to the 
sewage, and the surface 
hydraulic load can reach up to 1m3 /  (m2,d). Capability of 
denitrification and dephosphorization of the 
system can be largely increased, 
total nitrogen removal efficiency of the 
system can be higher than 80% as tested, the total phosphorous removal efficiency can be more than 90%, and discharged water can meet the qualifications of GB8978-1996 national 
sewage discharge standard. The 
system is low in project and operation costs and less in 
accommodation area, can realize automatically controlling of operation, and is adaptable to domestic 
sewage treatment of relatively concentrated 
discharge at towns and villages and scenic spots.