The invention discloses a zero-velocity/course correction application online calibrating method for optical fiber strapdown inertial measuring unit, and belongs to the field of inertial technology. A carrier erection two-position aligning process is utilized sufficiently, main error sources including drift errors, scale errors, mounting errors and the like of the optical fiber inertial measuring unit are calibrated by a filtering method on the basis of zero-velocity correction and heading correction, and the actual use precision of the optical fiber inertial measuring unit is improved. Output data of an optical fiber gyro and output data of a quartz accelerometer are acquired by determining parameters of the initial position of a carrier; the gesture of the carrier is determined by means of coarse alignment; and online calibration is realized by precise alignment for a horizontal position and a vertical position. The method is used for calibrating main error items of the optical fiber inertial measuring unit, so that the parameter identification precision of a system and an actual navigation performance of the optical fiber strapdown inertial measuring unit are improved.