The control of agricultural vehicle traveling speed is an important factor of navigation system and variable rate application system in precision agriculture. The traveling speed control algorithm of agricultural vehicle in the field requires a higher adaptive ability because of adverse circumstance. The rice transplanter speed control system was designed on the basis of the analysis of vehicle speed shifting mechanism. The variable universe adaptive fuzzy PID (VFPID) control method was introduced to improve the adaptability of the control algorithm. The road test of control system was accomplished on the platform of rice transplanter. The test results showed that the average error was less than 0.02m/s and the control method was feasible and effective. As compared with PID results, the traveling speed stabilized in a short period for the VFPID control method, and the control method was more adaptive with the changes of set point and engine speed.