An insulation detection circuit, detection method, and battery management system are disclosed in the present disclosure. The insulation detection circuit includes a positive sampling unit, a negative sampling unit, a positive sampling point, a negative sampling point, a reference voltage terminal, and a processor. A first end of the positive sampling unit is connected with positive electrode of the power battery pack to be measured. A second end of the positive sampling unit is connected with the reference voltage terminal and the positive sampling point. A first end of the negative sampling unit is connected with negative electrode of the power battery pack to be measured. A second end of the negative sampling unit is connected with the reference voltage terminal and the negative sampling point. The processor is connected with the positive sampling point and the negative sampling point.