In order to improve the performance of optical fiber macrobending temperature sensor, a novel optical fiber macrobending temperature sensor based on polyimide (PI) coating is proposed. The optical fiber bending radius of the sensor is determined by the optical fiber bending loss-temperature measurement method based on the core-cladding-infinite coating structure, and a new type of optical fiber macrobending temperature sensor is obtained by coating the PI film on the 1060-XP optical fiber cladding. The temperature sensing experimental results of the sensor show that PI coating can not only improve the mechanical properties and heat resistance of optical fiber, but also significantly improve the temperature sensitivity and temperature measurement resolution. The novel optical fiber macrobending temperature sensor can achieve a wide temperature measurement range of -20 ℃ and 100 ℃, and the temperature sensitivity is 0.072 dB/℃ and the resolution is 0.14 ℃. Compared with other optical fiber macrobending temperature sensors, the temperature sensing performance of the designed sensor is significantly improved.