A temperature sensor based on orbital angular momentum (OAM) modal interference is proposed, which demodulates the information using the image detection method. The sensing mechanism and demodulation principle of the sensor are studied, and the sensing performance and immunity to light-noise are analyzed. The simulation results show that the temperature can be demodulated by a single image using the phase information carried by the OAM modes. Moreover, the demodulated result is linearly dependent on the modal phase difference. The temperature sensitivity of the sensor is immune to the fluctuation of the modal intensity and external light-noise. The proposed OAM modal interference sensor has better stability and reliability than conventional modal interference sensor based on LP modes.