The disclosure discloses a method and device for detecting a state of an overcurrent protector for a battery, wherein a voltage Uout of a power supply and a voltage Ubat of a battery connected to the power supply via an overcurrent protector is acquired, and U=|Uout−Ubat| is calculated; when UL≦U≦UH and |Ibat|≦Imin, the voltage of the power supply is adjusted to be U′out, wherein UL and UH are the minimum value and maximum value of a difference between the voltage of the power supply and the voltage of the battery, respectively, Ibat is a current of the battery, and Imin is a current detecting precision for detecting a current equipment of the battery; the voltage of the battery U′bat after adjusting the voltage of the power supply is acquired, and U′=|U′out−U′bat| is calculated; and a state of the overcurrent protector for the battery is determined. With the disclosure, in the case that the difference between the voltage of the battery and the supply voltage is small, by regulating the supply voltage and comparing the voltage difference across the overcurrent protector again, accurate detection of the state of the overcurrent protector for the battery as well as reduction of detecting costs is enabled.