Abstract: The research on the optimal configuration of the scan parameter such as the projection number K and the number of measurement M of each angle projection was carried out with high precision industrial CT equipment with different intensity ray sources. The Matlab fan beam simulation platform was established. Based on different scan parameters, the CT projection and reconstruction under different intensity ray source conditions were simulated. These CT images were evaluated by the combination of subjective evaluation of human eye and objective evaluation algorithm. The optimal allocation rules and calculation formulas of the scan parameters of K and M under the condition of limited detection time were given. The cone beam CT test of X-ray machine and ⁶⁰Co ray source was introduced. The experimental results show that the CT scan parameter optimization method and the formula are effective, which provides a means for optimizing the use of high precision industrial CT equipment.