The invention discloses a reflective fiber sensor for liquid temperature measurement. The reflective fiber sensor comprises a fiber probe, a light source, a photoelectric conversion and filter-amplifier module, a division circuit, and an acquisition and display module. The fiber probe includes a transmitting fiber TF and two receiving fibers, namely, a first receiving fiber RF1 and a second receiving fiber RF2. The axis spacing between one receiving fiber and the transmitting fiber is different from the axis spacing between the other receiving fiber and the transmitting fiber. The first receiving fiber RF1 is arranged between the transmitting fiber RF and the second receiving fiber RF2, and the axes of the three fibers are in the same plane. The fiber probe further includes a sensor body, a reflector, and a liquid inlet sleeve, wherein the reflector and the sensor body are connected by the liquid inlet sleeve. The liquid inlet sleeve is provided with a plurality of liquid inlet holes. An incident fiber is connected with the light source. The output ends of the receiving fibers are connected with the acquisition and display module through the photoelectric conversion and filter-amplifier module and the division circuit in sequence.