The geometric state control of high-speed railway ballasted lines is the key task of daily operation and maintenance. This paper takes the Hefei-Nanjing high-speed railway on-site maintenance work as the background, proposes a geometric state maintenance control method for high-speed railway ballasted lines, compares and analyzes the uneven vector height deviation before and after the maintenance, and evaluates the maintenance effect in combination with the high-speed railway vehicle and track dynamic analysis. The research results show that the use of large machine tamping, manual fine-tuning operation, rail grinding and other control methods can effectively reduce the deviation of level, triangle pit, orbit, vertical vector height, and the improvement rate of most indicators is more than 40%, which effectively improves the running comfort of high-speed railway ballasted lines. The analysis of vehicle-track dynamics shows that the derailment coefficient and wheel load reduction rate after maintenance are reduced by about 50%, and the vertical vibration acceleration of the vehicle body has decreased by 66.67%, which effectively improves the running comfort and safety. The proposed method may provide reference for the maintenance and repair of ballasted high-speed railway.