Micrometer-sized optical temperature sensors with graphene have been designed and analyzed in order to reach the highest temperature sensitivity. The main idea is to control the temperature of any system by surface graphene material in a micro-two-ring resonator path. By rising the temperature of the system, graphene with 5000 W / mK temperature conductivity senses the increase and applies it in the sensor resonance peaks. The prominent features of these sensors are small dimensions, high finesse and sensitivity, safe from electromagnetic interference, high bandwidth, low weight, and low cost. Electronic sensors suffer from electrical disturbances and electromagnetic interference, and sometimes do not function properly. Therefore, this micrometer optical temperature sensor with 44 × 40 μm dimensions and high sensitivity and finesse in all industrial and medical fields is necessary. The materials used in this sensor are graphene, Si, and SiO<sub>2</sub>, which are natural elements and have very high temperature stability. Free-spectral range reaches to 820 GHz and full width at half maximum to 21 GHz, and this quantity increases the finesse and sensitivity of the system, the time delay of sensor is 1.21 ps, which shows the low light dispersion and fast performance time.