Because anti-aircraft artillery servo system requires high tracking accuracy and strong robustness, a fractional PIλ controller design method is put forward. A math model of artillery servo system is established and the fractional position controller structure is analyzed. Based on these constraints, such as phase margin, cut-off frequency, low frequency precision point, vibration index, etc, put forward and deduce design method of fractional controller integrate design method. The simulation results and test results show that the fractional controller can make servo system have high control precision, wide bandwidth and strong robust, it provides a new method for the design of anti-aircraft artillery servo system.