A variable valve lift actuator comprising: a first body to rotate at an angle within a preset angle range through rotation motion of a high speed cam coupled to a camshaft; a second body coupled to the first body or decoupled from the first body to rotate at an angle within a preset angle range such that a valve is open or closed through the rotation motion of the high speed cam when the second body is coupled to the first body; a latching pin provided retractably forward the first body through the second body such that the first body is coupled to the second body or decoupled from the second body; a driving module to retractably actuate the latching pin; a rotation shaft provided on the valve while traversing both sidewalls of the first and second bodies (20, 30) such that the first body is rotatable; and a return spring fitted around the rotation shaft to provide restoring force for the first body such that the first body rotated by the high speed cam returns to an original position thereof, wherein a deactivation control operation of the valve is performed to deactivate a cylinder by operating the latching pin to decouple the first body from the second body at a low-speed and low-load state of an engine, characterized in that the second body comprises a front wall, inner sidewalls, and outer sidewalls provided at a front surface and both sides of the second body, respectively, to be arranged corresponding to a front surface and both sides of the first body; a pressing plate mounted at each of both sides of the front wall of the second body to press an upper end of the valve through rotation motion of the second body; and a support plate provided at a rear end portion of the inner sidewall to be supported in contact with an upper end of a pivot support member, and wherein the return spring has a central portion protruding to be supported to the front surface of the second body, and both ends supported to support steps formed at the both sidewalls of the first body. a first body to rotate at an angle within a preset angle range through rotation motion of a high speed cam coupled to a camshaft; a second body coupled to the first body or decoupled from the first body to rotate at an angle within a preset angle range such that a valve is open or closed through the rotation motion of the high speed cam when the second body is coupled to the first body; a latching pin provided retractably forward the first body through the second body such that the first body is coupled to the second body or decoupled from the second body; a driving module to retractably actuate the latching pin; a rotation shaft provided on the valve while traversing both sidewalls of the first and second bodies (20, 30) such that the first body is rotatable; and a return spring fitted around the rotation shaft to provide restoring force for the first body such that the first body rotated by the high speed cam returns to an original position thereof, wherein a deactivation control operation of the valve is performed to deactivate a cylinder by operating the latching pin to decouple the first body from the second body at a low-speed and low-load state of an engine, characterized in that the second body comprises a front wall, inner sidewalls, and outer sidewalls provided at a front surface and both sides of the second body, respectively, to be arranged corresponding to a front surface and both sides of the first body; a pressing plate mounted at each of both sides of the front wall of the second body to press an upper end of the valve through rotation motion of the second body; and a support plate provided at a rear end portion of the inner sidewall to be supported in contact with an upper end of a pivot support member, and wherein the return spring has a central portion protruding to be supported to the front surface of the second body, and both ends supported to support steps formed at the both sidewalls of the first body.