In order to improve the measurement accuracy, the high accuracy measurement model of laser triangulation method was proposed, which consisted of variable threshold subpixel grayscale gravity center extraction algorithm and CCD tilt error compensation algorithm. The spot centering algorithm played a decisive role in the accuracy of laser detection. A variable threshold subpixel grayscale gravity center extraction algorithm was proposed according to the defect of the existing laser center localization algorithm. The gradient function and the Gaussian fitting algorithm were used to set the threshold to remove the effect of spot edge noise region on center location, and the polynomial interpolation were used to improve the precision of grayscale gravity method. CCD tilt error compensation algorithm was established to further improve accuracy. The system was established with STM32F407 as the hardware core. Taking taper thread as the measured object, the test was carried out. The results show that the laser spot can be accurate acquisition by the high accuracy measurement model. Precision is obviously higher than the traditional grayscale gravity center method, and successfully controls the error within 10 microns.