The optical tracking system and a control method are disclosed. An optical tracking system medical tool, a first marker, the second marker is placed on the affected part, an optical tracker for generating a first marker detection signal by detecting a position of the first markers, the medical tool attached to one end of the medical tool the mounted towards the other end, the vision sensor and the generated from optical tracker first marker detection signal and detecting the second marker generated by the vision sensor signal for generating a second marker detected signal to detect the position of the second marker the reception, and on the basis of the first marker detection signals, and calculates the first position data of the medical tool, and on the basis of the second marker detection signal calculates the second position data of said medical tool, the first location based on the data, and the second position data and a processor for detecting the position of the medical tool.