Abstract : This paper improves and refines the deviation function of the appropriate-point comparison interpolation algorithm, proposing an optimized interpolation algorithm. This improves the interpolation accuracy from less than or equal to one pulse equivalent to less than or equal to 0.5 pulse equivalents, and reduces the number of interpolation nodes by 40%–50%. It eliminates problems such as system lag, step loss, and crawling caused by the algorithm during high-speed, high-precision interpolation, while maintaining the algorithm's simplicity. Keywords : Point-to-point comparison interpolation, deviation function, algorithm optimization. In the development of SK-20, SK-∞A/B, SK-30, and SK-30A/B CNC systems, it was found that the commonly used point-to-point comparison interpolation algorithm can meet the requirements well when the pulse equivalent is 0.01mm and the system feed F ≤ 3000mm/min. However, when the pulse equivalent is 0.005-0.001mm and the system feed F > 3000mm/min, the number of interpolation points increases sharply. More than 80% of the CPU time is spent on dynamic coordinate calculation and step pulse output, consuming a large amount of resources. Furthermore, in multi-axis linkage, the system is prone to problems such as lag, step loss, and creep, affecting the system's response speed and interpolation accuracy. This paper proposes an optimized interpolation algorithm that enables the system to maintain good response speed and interpolation accuracy even when the pulse equivalent is 0.001mm and the feed speed F ≤ 8000mm/min. I. Establishment and Analysis of the Mathematical Model for Point-by-Point Comparison Interpolation Algorithm For ease of analysis, interpolation is assumed to be performed in the first quadrant. 1. Linear Interpolation (as shown in Figure 1) Let the starting point of line 0A be 0 (0, 0), and the ending point be A(x_e, y_e). Let P(x_i, y_i) be a moving point (i.e., the interpolation point). Then the following equation holds: [b][align=center]For more details, please click: Optimization Design of Interpolation Algorithm in CNC System[/align][/b]