The invention provides a real-time optimizing system for the external parameter of an endoscope. The system includes an optical tracker, a first tracking marker, a second tracking marker and an optical chessboard lattice. The first tracking marker is fixed on an endoscope tube, and the second tracking marker is fixed on the optical chessboard lattice. According to the provided real-time optimizingsystem for the external parameter of the endoscope, the external parameter of the endoscope is tracked and calculated in real time through the two markers, the device is simple, the method is practical, and operation is easy to achieve. According to a real-time optimizing method for the external parameter of the endoscope, the internal parameter of the endoscope is calculated, the main axis position of the endoscope is calculated, the real-time external parameter of the endoscope is obtained according to the internal parameter and the main axis position of the endoscope, the rotation angle, relative to the initial position, of the endoscope is detected out only through an image in the surgery, the external parameter of the endoscope can be automatically calibrated, human intervention is not needed, and it is convenient for doctors to operate.