The invention provides a 
sewage treatment tank with a steel fixing structure, which comprises a tank body, a water inlet 
pipe, a water outlet 
pipe, a 
sludge pipe, a rotating frame, a center table, a driving mechanism, a 
sludge removal mechanism, a transmission mechanism, a 
sludge suction mechanism, a sludge guide mechanism, a sludge 
discharge mechanism and a sludge scraping 
assembly, in the rotating process of the rotating frame, the sludge scraping 
assembly is driven to conduct sludge scraping work on the bottom of the 
pool body, the transmission mechanism drives the sludge removing mechanism to conduct sludge scraping work on sludge on the side wall of the 
pool body, and the sludge suction mechanism on the rotating frame concentrates the scraped sludge to the sludge guide mechanism and discharges the sludge through the sludge discharging mechanism. The sludge removal mechanism, the sludge suction mechanism and the sludge scraping 
assembly rotate along with the rotating frame so that comprehensive sludge removal work can be conveniently carried out on the tank body, a good sludge flow guide effect is achieved, the sludge removal effect and the sludge 
discharge efficiency of the tank body are improved, and good 
water quality purification performance is achieved.