With the requirements for better performance of the temperature sensor, developing a new high-performance temperature sensor is of great significance. Using graphene as the nanofiller and epoxy resin as the matrix, various graphene/epoxy nanocomposite sheets with different graphene additions were prepared by ultrasonic and planetary stirring method. Electrodes were attached at both ends of the graphene/epoxy nanocomposite sheet to make the temperature sensor. The effects of graphene additions on the temperature-resistance properties of the nanocomposite sheets were investigated at the temperature range of 30℃ to 100℃. The results show that the temperature sensor exhibited a negative temperature coefficient (NTC) effect with the increasing temperature, and the resistance decreased in an approximately linear trend. In addition, it is found that the higher the graphene content, the smaller the magnitude of the resistance change. After three thermal cycle treatments, the temperature-resistance relationship of the sensor tended to be stable.