An optical fiber reinforcement processing apparatus and reinforcement processing method are provided where it is not necessary to dispose a temperature detecting device such as a thermistor, and a heating control in which the detected temperature is not varied, the power consumption is low, and which is accurate is enabled.An optical fiber reinforcement processing apparatus in which a fusion-spliced portion of an optical fiber is covered by a heat-shrinkable reinforcing sleeve to perform reinforcement has: heating controlling means for performing a heating control on a heater which heats the reinforcing sleeve; and temperature detecting means for detecting a heating temperature of the heater on the basis of a change of the resistance of the heater. The heating control and the temperature detection are performed by controlling time periods of turning on/off a power supply to the heater. The temperature detection is performed by detecting a voltage change Eo of the midpoint of a bridge circuit in which a series circuit of a first fixed resistor R1 and a heater resistor RX, and a series circuit of a second fixed resistor R2 and a third fixed resistor R3 are connected in parallel.