The present disclosure provides a thermal runaway detection circuit and a method, which is directed to field of batteries. The circuit includes: a sensing module including a terminating resistor; a detection module including a first voltage dividing resistor set and a second voltage dividing resistor set; and 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. The thermal runaway detection data includes first sampled data and second sampled data. The technical solutions in the present disclosure can improve safety of the battery pack.