The present invention belongs to an angle detection device, belonging to the detection technology field. The angle detection device comprises a rotary transformer and a signal processing device. The rotary transformer comprises at least four leads, where at least two of the leads are excitation leads, and at least two of the leads are signal leads. The signal processing device comprises: an excitation circuit configured to connect with the excitation leads and provide excitation signals for the excitation leads; a signal collection circuit configured to control the signal leads and collect position signals of the rotary transformer from the signal leads; and an angle calculation circuit configured to connect the signal collection circuit and calculate the rotation angle of the rotary transformer according to the position signals emitted by the signal collection circuit. The angle detection device can provide an efficient signal processing technology for an inductance rotary transformer, especially to an inductance rotary transformer having four leads consisting of two excitation leads and two signal leads to obtain accurate rotation angle of the rotary transformer.