The guiding principle of rail vehicle is explained. Based on the principle, the main factors affecting the wheel guiding force are presented. Then the contact geometry of S1002/UIC60E2 is analyzed. It's shown that the radius of flange of wheel profile S1002 is smaller than the corner of rail UIC60E2. Therefore, the two-point contact between the wheel and rail is observed, which decreases the longitudinal creep force and increases the wheel guiding force, so that the risk of derailment is increased consequently. To improve the curving performance of S1002/UIC60E2, a new method optimizing wheel profile for the targeted wheel/rail contact geometry is presented. The optimized wheel profile with this method can avoid the two-point contact problem and improve the curving performance by decreasing the wheel guiding force. A computer program based on this method has also been developed. The curve negotiation test on track by DBST showed that the wheel guiding force of the optimized wheel profile decreased significantly.