The finite difference method combination linear perturbation method was used to analyze the effect of manufacturing errors (sine waviness,square waviness,triangular waviness) and journal misalignment on critical inertia force and critical whirl ratio of hydrostatic pressure aerostatic spindle.The results indicate that the critical inertia force increases while the critical whirl ratio decreases with the growth of eccentricity ratio.Moreover,the higher the rotation speed is,the larger the critical inertia force is.However,the critical whirl ratio increases first and then decreases slightly with the growth of rotation speed. Small eccentricity ratio and high rotation speed are helpful for improving the stability of aerostatic spindle. Sine waviness improves the critical whirl ratio most obviously,followed by square waviness and triangular waviness.Furthermore,the smaller the period of manufacturing errors is,the better the stability of the spindle is.The stability of aerostatic spindle degrades with the increases of the waviness amplitude while the effects of waviness amplitude on spindle stability can be neglected if errors with small period.The journal misalignment abates the spindle stability.The effect of misalignment in the x and y directions simultaneously on the stability are greater than it in the x or y direction.