By adding composite powder carriers to the biological pool, while increasing the concentration of the mixed liquid in the biological pool, a microbial system with "double sludge" symbiotic growth and attached growth was built; and through the sludge concentration and separation unit and composite powder carrier recovery unit, Double sludge age has been achieved and the efficiency of biological denitrification and phosphorus removal has been enhanced. The sludge concentration of the HPB technology biological pool is 6-10g/L, MLVSS/MLSS is 0.30-0.38, BOD5 sludge load is 0.04- 0.2 kgBOD5/(kgMLSS·d), the sludge age is 15-21 days, the sludge reflux ratio is 50%-100%, the mixed liquor reflux ratio is 100%-400%, and the hydraulic retention time is 5-8 hours. Strengthen the effect of biological denitrification and phosphorus removal, and the effluent can stably meet the quasi-IV standard. Compared with the traditional activated sludge method, carbon source consumption is reduced by more than 35%, and carbon emissions per ton of COD can be reduced by 3.2 tons, which greatly improves the level of carbon emission reduction. Sewage treatment projects with the same emission standards save 30% of floor space, 20% of investment and operating costs, and shorten the project construction period by more than 30%.