The invention provides a method for optimizing insertion loss of an optical circulator. A clamping device, a laser bombardment device and a force sensor are included, and the method is characterized in that the optical circulator is fixed on the clamping device along a section direction; a laser pulse transmitter is aligned with a metal packaging tube of the optical circulator; the force sensor is in contact with the optical circulator, and is specifically in contact with an optical fiber collimator at the bombarded end of the optical circulator; change information of an insertion loss value of the optical circulator is obtained through the force sensor and the clamping device; the clamping device and the force sensor are repeatedly adjusted till elastic force measured by the clamping device and the force sensor is equal in magnitude and opposite indirection; and the laser pulse transmitter is utilized to bombard the metal packaging tube, and the specific position is at the gap between the optical fiber collimator and a crystal module. The method changes the relative angle of the optical fiber collimator and the metal packaging tube by use of laser pulses, thereby indirectly changing the relative angle of the optical fiber collimator and an optical fiber collimator (or reflector), and finally achieving the purpose of optimizing insertion loss.