Unmanned helicopter control system is a nonlinear system that is susceptible to environment interference and coupling each channel. An anti-interference controller is needed to realize unmanned helicopter autonomous fly in different circumstances. The linear system model of helicopter’s transverse and vertical channel is obtained by using system identification method. Based on linear quadratic regulator theory, design a LQR optimal controller for attitude of helicopter’s transverse and vertical channel. Have done lots of flight tests in ALIGN 700N helicopter after select the optimal controller parameters in MATLAB software. Simulation and flight tests show that LQR control technology designed unmanned helicopter attitude controller has strong robustness and practicality.