The proposed temperature sensor utilizes the enhanced harmonic vernier effect in an optical fiber system, combining an optical fiber Sagnac interferometer (SI) with a Fabry-Perot interferometer (FPI). By aligning the FPI's free spectral range as a multiple of the SI's, with opposite temperature responses, the enhanced harmonic vernier effect is achieved. Experiments show that this effect and the enhanced normal vernier effect have comparable temperature sensitivity, being 28.7 and 16.9 times greater than those of single FPI and SI, respectively. In addition, the magnification of the enhanced harmonic vernier is 3.4 and 1.8 times that of the normal harmonic vernier. However, the detuning of the Panda fiber length for the enhanced harmonic vernier effect is significantly larger than for the enhanced normal vernier effect, with detuning increasing with order. The enhanced harmonic vernier's magnification is also easier to control at higher orders. The sensor demonstrates high sensitivity, excellent stability, and low preparation cost, offering promising prospects for practical applications.