The invention provides a locating device hinted by color for the fiber optics probe in medical diagnostic device, comprising a hub installed outside the fiber optics probe, the front end of the hub is equipped with a cradle, which is vertical to the output light direction of the fiber optics probe, the two ends of the are equipped with a first semiconductor laser designator and a second semiconductor laser designator individually, which are set along isosceles triangle and equipped with same connecting system, the laser indicating direction are intercepted on the output light direction, the visible laser of different color in the crossing point overlapping for direct observation of the hint crossing point. Adjusting the angle of semiconductor laser designator according to the needed distance from fiber optics probe surface to detected surface, to make the crossing point drop on the detected surface. The device is characterized by the simple structure and direct and convenient usage. |