The invention discloses a three-dimensional rotary type net-shaped contact body device, a biological rotating disc tank and sewage treatment equipment, and relates to the technical field of environmental protection equipment. The three-dimensional rotary type net-shaped contact body device comprises a rotating disc body and a biological contact disc, wherein the biological contact disc is arrangedon the rotating disc body; the rotating disc adopts a welding structure, is made of high-strength low-alloy structural steel materials and is high in strength and long in service lifetime; a supporting shaft adopts a hollow stainless steel pipe welding structure, and is light in weight and high in strength; the biological contact body is axially fixed in a manner of compressing a connecting discwith internal and external threads, so that the biological contact body is more reliable in connection and convenient to disassemble, assemble and maintain. The biological rotating disc tank comprisesa tank body and a biological rotating disc, wherein a mixed solution is arranged in the tank body, bacillus is in the mixed solution, one part of the biological rotating disc is immersed in the mixedsolution, and the other part of the biological rotating disc is exposed in the air; the biological rotating disc comprises a main shaft and a membrane, and the membrane is of a three-dimensional netstructure and adsorbs the bacillus; a driving mechanism is connected to one end of a main shaft of the biological rotating disc and used for driving the main shaft to rotate.