The widely adopted drive method for the spindle motors with sinusoidal back-EMF in hard disk drive is to inject current into two phases and use the third phase to detect the rotor position. The commutation position to switch phases is normally 30 electrical degrees after the zero crossing points (ZCPs) of the silent phase back-EMF. To minimize the current ripple and thus the torque ripple, the commutation positions should be accurate and less prone to ZCP jitters. In this paper, an effective method based on the flux-linkage increment (FLI) is presented to realize accurate and robust commutation position detection. This method can greatly reduce the commutation position jitter even with obvious ZCP error. Experimental results show that the FLI method work well over a large speed range.