The disclosure provides a thermal runaway detection circuit and method, and relates to batteries. The thermal runaway detection circuit includes: a sensing module including a sensing cable; a detection module connected to the sensing cable and including at least one set of voltage dividing resistors; a processing module connected to the detection module, wherein the processing module is configured to obtain thermal runaway detection data, and determine whether thermal runaway occurs in the battery pack based on the thermal runaway detection data, wherein the thermal runaway detection data includes battery pack data and sampled data collected from sampling points, and the sampling points are disposed between the two connected voltage dividing resistor sets. The technical solutions in the present disclosure can improve safety of the battery pack.