During the processing of TC4 titanium alloy by cylindrical turning, the occurrence of regenerative flutter will leave irregular vibration marks on the surface of the workpiece, which seriously affects the surface processing quality of titanium alloy.The mechanical model of regenerative chatter vibration of TC4 titanium alloy was established considering the influence of dynamic parameters of cylindrical turning.The dynamic parameter identification experiment was carried out on the KDN numerical control lathe, the experimental results were put into the analytical solution of the established model, and the stability lobe diagram of the cylindrical turning was drawn with MATLAB software, and the ultimate cutting depth of the cylindrical turning TC4 titanium alloy was obtained to be 0.553 2 mm.The test results time domain analysis and roughness analysis were carried out.The experimental results shows that when the cutting depth is less than 0.553 2 mm, the turning is relatively stable no matter what the speed is;when the cutting depth is greater than 0.553 2 mm, but the point formed by the rotation speed is located below the curve of the blade lobe diagram, the mean amplitude and roughness are small, which is not far from the former, and the turning is stable;when the point composed of cutting depth and rotation speed is located above the lobe diagram curve, compared with the point with the same rotation speed below the lobe diagram curve, the average amplitude increases by about 1 times, the roughness value increases by about 31%, and the turning is unstable.The experimental results verify the reliability of the stability lobe diagram, which has certain guiding significance to actual processing.