Abstract: Described here in the article are the main steel pipe-cutting processes, and the significant advantages of the cutting process featuring steel pipe-fixing, and tool turning and feeding. The mechanical structure of the said cutting machine’s tool feeding drive system is analyzed. And the three working stages of one single cutting cycle of the cutting machine are elaborated, and relevant model is set up. And the displacement functional relationship between the tool and the feed servo cylinder is calculated with the model. A great amount of displacement data are obtained by the computer programming, and the displacement relationship curve and speed change curve are described. The speed curve is simulated and optimized with the curve fitting method. Finally, the actually applicable speed function is obtained, and is used in the servo controller, resulting in excellent effect.