Abstract: A new iterative algorithm of finite difference method used to numerically solve the lubrication problems of magnetic head/disks under ultra thin gas film thickness is presented.Unlike the conventional difference finite method,the pressure included in the Couette flow term now serves as main iterative part.This will effectively solve the problem of numerical oscillation at a high bearing number.In the most occasions,the numerical method converges stably and calculates quickly.Pressure distributions and bearing stiffness are calculated on the occasions that a slider deviates slowly or abruptly from its balance position.Results show that the lower the slider's reference height or pitch angle is,the higher the bearing stiffness is.Small movements perpendicular to the disk can not make slider lose balance,while different pitch angles can make much difference on the bearing force implying on the slider,which should be controlled by designers.Abrupt variations of sliders flying attitude may cause apparent squeeze effects,whose intension is related to the steady flying attitude before the variations.