A linear actuator includes a sliding rod, a motor and a buffer assembly. The motor connects the sliding rod to drive the sliding rod. The buffer assembly is disposed at an end of the sliding rod and includes an elastic element and an outer sleeve. The elastic element is received in the outer sleeve. The sliding rod connects the outer sleeve. The outer sleeve is movable along an axial direction of the sliding rod. The elastic element separately pushes an inner wall of the outer sleeve and the sliding rod. The elastic element is pre-compressed along the axial direction of the sliding rod. The buffer assembly can absorb vibration and impact caused by the motor driving the sliding rod.