A circuit for detecting thermal runaway in a battery set, characterized by comprising: a sensing module comprising a sensing line (a, b, c, d, e), wherein a distance between at least a portion of the sensing line (a, b, c, d, e) and a single battery cell in the battery set is less than a temperature-sensing distance threshold; a detection module connected to the sensing line (a, b, c, d, e) and comprising at least one group of voltage-dividing resistor sets, wherein one end of each group of voltage-dividing resistor sets is configured to be connected to a first power-supply terminal, the other end of each group of voltage-dividing resistor sets is configured to be connected to ground, and each group of voltage-dividing resistor sets comprises at least two voltage-dividing resistor sets connected in series, wherein each of the at least two voltage-dividing resistor sets comprises at least a resistor (R1, R2, R3, R4, R5, R6, R7, R8, R18, R19); characterized by: a processing module connected to the detection module and configured to acquire thermal runaway detection data, wherein the thermal runaway detection data comprises sampled electrical signal data collected from one or more sampling points (AD1, AD2, AD3, AD4, AD5, AD6, AD7) disposed respectively between two connected voltage-dividing resistor sets, wherein the sensing line (a, b, c, d, e) is connected to the sampling points (AD1, AD2, AD3, AD4, AD5, AD6, AD7); determine an on-off state of the sensing line (a, b, c, d, e) based on the sampled electrical signal data, the on-off state comprises short-circuit, disconnected or normal connection; and determine whether thermal runaway has occurred for the battery set based on the on-off state of the sensing line (a, b, c, d, e). a sensing module comprising a sensing line (a, b, c, d, e), wherein a distance between at least a portion of the sensing line (a, b, c, d, e) and a single battery cell in the battery set is less than a temperature-sensing distance threshold; a detection module connected to the sensing line (a, b, c, d, e) and comprising at least one group of voltage-dividing resistor sets, wherein one end of each group of voltage-dividing resistor sets is configured to be connected to a first power-supply terminal, the other end of each group of voltage-dividing resistor sets is configured to be connected to ground, and each group of voltage-dividing resistor sets comprises at least two voltage-dividing resistor sets connected in series, wherein each of the at least two voltage-dividing resistor sets comprises at least a resistor (R1, R2, R3, R4, R5, R6, R7, R8, R18, R19); characterized by: a processing module connected to the detection module and configured to acquire thermal runaway detection data, wherein the thermal runaway detection data comprises sampled electrical signal data collected from one or more sampling points (AD1, AD2, AD3, AD4, AD5, AD6, AD7) disposed respectively between two connected voltage-dividing resistor sets, wherein the sensing line (a, b, c, d, e) is connected to the sampling points (AD1, AD2, AD3, AD4, AD5, AD6, AD7); determine an on-off state of the sensing line (a, b, c, d, e) based on the sampled electrical signal data, the on-off state comprises short-circuit, disconnected or normal connection; and determine whether thermal runaway has occurred for the battery set based on the on-off state of the sensing line (a, b, c, d, e). a processing module connected to the detection module and configured to acquire thermal runaway detection data, wherein the thermal runaway detection data comprises sampled electrical signal data collected from one or more sampling points (AD1, AD2, AD3, AD4, AD5, AD6, AD7) disposed respectively between two connected voltage-dividing resistor sets, wherein the sensing line (a, b, c, d, e) is connected to the sampling points (AD1, AD2, AD3, AD4, AD5, AD6, AD7); determine an on-off state of the sensing line (a, b, c, d, e) based on the sampled electrical signal data, the on-off state comprises short-circuit, disconnected or normal connection; and determine whether thermal runaway has occurred for the battery set based on the on-off state of the sensing line (a, b, c, d, e).