The relationships between drill speed, whirl, squeeze effect and fluid force drill suffered were gotten by using cutting fluid Reynolds equation. Principle of deep-hole drilling drill whirl was studied, pointing out the promotion of positive procession cutting fluid component was drill whirl’s reason. The drill whirl round shapes at different times were simulated and studied,suggesting that only when BTA drill was suffered by the fluid force,stable motion could be obtained.The anti-procession of the drill was analyzed, and the squeeze film damper work principle was revealed.The movements of the drill before and after adding squeeze film damper were comparatively studied by using MATLAB simulation software.