The invention provides an angle detection device, a rotating body and a motor system, which belongs to the technical field of detection. The angle detection device comprises a rotation angle detection device and a signal processing device. The rotation angle detection device comprises at least one set of detection coil system. Each set of detection coil system comprises at least four rows of multi-arm bridge circuits which are connected in parallel and are composed of a number of coils. Two lead wires are led out from two contacts, which are connected in parallel, of the multi-arm bridge circuits and are used as excitation leads. A lead wire is led out from each contact of upper and lower arms of each row of arms leads and is used as a signal lead wire. The signal processing device comprises an excitation circuit, a signal collection circuit and an angle calculation circuit. The differential signals of two signal lead wires and the differential signals of other two signal lead wires vary with the rotation angle of a rotor. The rotating body comprises the angle detection device and the rotating body. According to the invention, the measuring accuracy and the reliability are high; signal processing and calculating can be effectively carried out on an inductive rotation transformer; and the structure is simple.