Numerical Control (NC) equipments sharing over Internet is a potential approach for improving the utilization of capacity, which is still a complex NP hard difficulty due to the complexity of schedule. This research takes the Constraints Satisfied Problem (CSP) thinking to solve the above problem employing grid technology. First, regarding the NC equipments sharing as CSP, the CSP model for NC equipments grid is developed taking the flexible constraints as the optimum objective and the rigid constraints as the boundary conditions. Second, the detailed algorithm and steps for optimization of NC equipments grid workflow based on Just-In-Time (JIT) thinking are proposed. Finally the digital experiment demonstrates the advantages of the CSP-driven methodology that has the higher efficiency for searching optimum solution.