The present invention directs an anti-shock method for head stack assembly which carries a slider for flying on a disk for operation, and the anti-shock method includes: inputting a constant current to a head disk interface sensor which is deposited in the slider; obtaining a changing voltage of the head disk interface sensor, which is changed with the temperature of the head disk interface sensor as the slider is shocked; outputting the changing voltage to a controller with a threshold set therein; if the changing voltage is bigger than the threshold for a specified number of times, the controller is triggered to control the head stack assembly to stop operating and load on a ramp beside the disk; while if the changing voltage is small than the threshold for said specified number of times, the controller is not be triggered and the head stack assembly still operates.