The invention discloses a resistance wire temperature sensor, comprising a housing, a copper heat conduction pipe, a movable sleeve, a movable brush, first to fourth resistance wires and an A/D converter. The heat conduction pipe is fixed on the housing, and is partially located in the housing; the movable sleeve sleeves the heat conduction pipe, and can slide relative to the heat conduction pipe; the heat conduction pipe and the movable sleeve are in hermetic seal cooperation; the movable brush is fixed on the movable sleeve; the first to fourth resistance wires are all fixed in the housing; one end of the first resistance wire and one end of the fourth resistance wire are both in electric connection with the A/D converter; one end of the second resistance wire and one end of the third resistance wire are in electric connection; the movable brush is in connection with the first to fourth resistance wires, allowing series connection among the first to fourth resistance wires; in addition, the movable brush can move relative to the first to fourth resistance wires. The resistance wire temperature sensor has high detection sensitivity.