Based on spatial mode interference,tilt-locking technique is a flexible and convenient way to stabilize laser frequency or to lock optical cavity.In this paper a modification of tilt-locking is described and experimentally demonstrated.The method uses a non-resonant first-order spatial mode TEM01 as phase reference,and utilizes the interference of the TEM01 mode and the TEM00 mode for locking.An obstacle is added in the reflected light path of the optical cavity to block half of the reflected light beam.The passing half of reflected beam is detected by a single-pixel detector,instead of a split detector,to derive the error signal for locking TEM00mode resonant frequency of optical cavity to laser frequency.An optical cavity can be stably locked over four hours with this method.This modification makes tilt-locking technique become more convenient and flexible.