Most of traditional servo valves are slide valve type. Although they have high control precision, stable performance, their working bandwidth are limited. So it is difficult to meet the demand of high frequency hydraulic system. In order to solve this problem, a high frequency excitation rotary valve with two degrees of freedom was proposed. The working principle was analyzed and its mathematical model was established, then the pressure at the valve port was simulated and experimentally studied. The results show that the reversing frequency of the rotary valve can be increased by increasing the spool speed valve or increasing the number of spool grooves. The pressure at the valve port exhibits a regular triangular change. The maximum pressure at the valve port decreases with the increase of the reversing frequency, and increases with the increase of the system pressure and axial opening. The minimum pressure at the valve port increases with the increase of the frequency and the system pressure, and decreases with the increase of the axial opening.