The invention discloses a multi-temperature impedance characteristic sensing cable, and a temperature detector using the sensing cable; the sensing cable is composed of 2 to 6 metal conductors, recoverable insulating layers with different temperature impedance characteristics, as well as 1 to 2 layers of outer jackets; each metal conductor sequentially comprises 1 to 2 insulation layers which are twisted into ropes; the twisted ropes are arranged in the 1 to 2 layers of outer jackets; the temperature detector is composed of a temperature sensing interface unit, sensing cables corresponding to the temperature impedance characteristics, and the cable terminal units; and the temperature sensing interface unit is mainly composed of a signal amplification and linearization circuit, an analog/digital conversion circuit, a microprocessor circuit (MCU), a display and operation circuit, a pulse output circuit and a timer circuit. The temperature detector can achieve the differential temperature, stationary temperature or differential stationary temperature alarm of the low, medium, high temperature ranges.