A parameter selection method for an insulation detection circuit, wherein the insulation detection circuit comprises a signal generation module, a voltage division module, an isolation module, a first sampling point, a second sampling point and a processor, wherein the isolation module comprises a first end configured to be connected to a positive electrode of a power battery under test and a second end connected to the second sampling point and is configured to isolate a high-voltage signal of the power battery under test; the signal generation module is connected to the first sampling point and configured to inject a low frequency AC signal to the power battery under test and provide the first sampling point with a first sampled signal of a predetermined frequency; the voltage division module comprises a first end connected to the first sampling point and a second end connected to the second sampling point and is configured to provide the second sampling point with a second sampled signal; and the processor is configured to calculate an insulation resistance of the power battery under test according to the first sampled signal and the second sampled signal, and wherein the parameter selection method comprises: determining, by a parameter selection device including a memory and a further processor, an allowable injection frequency range of the low frequency AC signal to be injected, according to a predetermined resistance range of the insulation resistance of the power battery under test and a predetermined resistance calculation cycle duration of the insulation resistance; and selecting, by the parameter selection device, an output frequency of the signal generation module according to a lowest frequency to be generated by the signal generation module and the allowable injection frequency range, wherein the selecting, by the parameter selection device, an output frequency of the signal generation module according to a lowest frequency to be generated by the signal generation module and the allowable injection frequency range comprises: obtaining, by the parameter selection device, a maximum frequency among the lowest frequency to be generated by the signal generation module, a frequency corresponding to a predetermined minimum signal injection cycle duration, and a frequency corresponding to a predetermined minimum resistance calculation cycle duration; determining, by the parameter selection device, whether the maximum frequency is within the allowable injection frequency range; and applying, by the parameter selection device, the maximum frequency as the output frequency of the signal generation module if the maximum frequency is within the allowable injection frequency range. determining, by a parameter selection device including a memory and a further processor, an allowable injection frequency range of the low frequency AC signal to be injected, according to a predetermined resistance range of the insulation resistance of the power battery under test and a predetermined resistance calculation cycle duration of the insulation resistance; and selecting, by the parameter selection device, an output frequency of the signal generation module according to a lowest frequency to be generated by the signal generation module and the allowable injection frequency range, wherein the selecting, by the parameter selection device, an output frequency of the signal generation module according to a lowest frequency to be generated by the signal generation module and the allowable injection frequency range comprises: obtaining, by the parameter selection device, a maximum frequency among the lowest frequency to be generated by the signal generation module, a frequency corresponding to a predetermined minimum signal injection cycle duration, and a frequency corresponding to a predetermined minimum resistance calculation cycle duration; determining, by the parameter selection device, whether the maximum frequency is within the allowable injection frequency range; and applying, by the parameter selection device, the maximum frequency as the output frequency of the signal generation module if the maximum frequency is within the allowable injection frequency range. obtaining, by the parameter selection device, a maximum frequency among the lowest frequency to be generated by the signal generation module, a frequency corresponding to a predetermined minimum signal injection cycle duration, and a frequency corresponding to a predetermined minimum resistance calculation cycle duration; determining, by the parameter selection device, whether the maximum frequency is within the allowable injection frequency range; and applying, by the parameter selection device, the maximum frequency as the output frequency of the signal generation module if the maximum frequency is within the allowable injection frequency range.