The invention relates to the field of concrete, and discloses a building garbage and wastewater concrete production method. The method comprises the following steps: breaking, namely, breaking waste concrete into broken pieces with the diameters less than 50 mm; performing manual or magnetic sorting, and removing reinforcing steel bars and large impurities from the broken pieces; performing pneumatic sorting, and removing dust and light impurities which are attached to the surfaces of the broken pieces; breaking and screening, and placing the broken pieces into a breaking machine for breaking, performing two-stage screening on broken recycled aggregate, wherein the pore diameter of a first-stage screen mesh used in the first-stage screening is 10 to 25 mm, a broken stone material is obtained after the first-stage screening, and the pore diameter of a second-stage screen mesh used in the second-stage screening is 5 to 16 mm, and light coarse aggregate is obtained after the second-stage screening; batching, namely, mixing the following components: the light coarse aggregate, the broken stone material, 34 to 36 of P.O 42.5 cement, 12 to 15 of coal ash, 8 to 10 of ceramic sand, 0.7 to 0.8 of a polyhydroxy salt type water reducer, 0.1 to 0.15 of cellulose and 20 to 22 of water; stirring, namely, stirring all materials uniformly to form slurry. The invention aims to provide the method for preparing full lightweight aggregate concrete by utilizing the waste concrete and the wastewater.