The influence of alignment errors of actuators and displacement sensors on the output accuracy of hemispherical resonator gyroscope is analyzed by the analysis of error mechanism and calibration experiment on a single-axis rate turntable. The dynamic motion equation of the ring shaped resonator is used at first, the radial vibration equation of resonator is established while the align ment errors of two actuators and two displacement sensors are taken into account, and according to the close loop testing principle of gyroscope, the error of output angular rate is calculated at last, calculated results show that the a lignment errors give rise to the error concerned with the square of the input an gular rate, thus lead to the nonlinearity of the gyro output. The calibration experiment in a single-axis rate turntable also indicates that the output has the error concerned with the square of input angular rate. Concerned discussions aiming at overcoming these nonlinear errors are conducted.