A method for calibration of a digital sun sensor is disclosed. The method comprises following steps. First, an integrated mathematic model for imaging of a sun sensor is established according to the external and internal parameters of the calibration system of the sun sensor. Next, the two axis of the rotator are rotated by different angles. Then, calibration points' data are acquired and sent to a processing computer through an interface circuit. Finally, a two-step calibration program is implemented to calculate the calibration parameters by substituting the calibration points' data to the integrated mathematic model. The disclosure also relates to an application device of the calibration method. The device comprises: a sun simulator to provide the incident sunlight, a two-axis rotator to acquire different the calibration points' data, and a processing computer to record the calibration points' data and calculate the calibration parameters. The calibration method and device apply to many kinds of digital sun sensors. By integrated external and internal parameters modeling, the disclosure improves calibration precision. Meanwhile, the whole calibration process is simplified because precise installation and adjustment is not required.