The calibration of optical axis parallelism plays an important role in multi-sensor photoelectric systems. Herein, a method for calibrating the optical axis parallelism based on interference fringes is proposed for calibrating the optical axes of passive multi-sensor photoelectric devices to meet the general application requirements of optical systems. The reference optical axis is established based on a collimation method. Newton ring interference fringes form by the reflection of the receiving optical system are fitted. Thus, the angle between the optical axis is calculated. The calibration axis of a laser distance-measuring machine is used to calibrate the optical axis of a transmitter and receiver. Experiment results show that the measurement accuracy for the receiving optical axis parallelism and the reference optical axis is better than 5″, satisfying the application requirements for calibrating multi-sensor photoelectric systems. The results also verify the effectiveness of the proposed method, whose visual calibration process can improve the calibration efficiency of passive optical devices and has the advantages of simple operation, practicability, and high measurement accuracy.