The invention discloses a portable fiber heating flexible apparatus including a portable case, a heating rod and a temperature measurement probe, each of the two sides of the heating rod is provided with a hole with a notch, the holes respectively receive the temperature measurement probe and a fiber to be heated to form a flexible integral body; the heating rod and the temperature measurement probe are connected with the portable case through a power supply line, and a power supply module and a display module are arranged in the portable case. The apparatus can be applied to the detection scheme for applying the fiber line type temperature-sensitive fire detector to tunnel cables and outdoor cables or other on-site environments, and can be used by work personnel to heat the temperature-sensitive fire, so that the related performance of the on-site verification temperature measurement object can be conveniently realized, and the aims of low cost and easy carrying can be achieved.