Linear actuator with stop mechanism

The utility model provides a linear actuator with a stop mechanism which is used for mechanically fixing a piston rod relative to a cylinder in the linear actuator. The piston rod comprises a piston rod body and a cylinder shell, wherein the piston rod body and the cylinder shell are coaxially arranged, and one end of the piston rod body and one end of the cylinder shell are fixedly connected. The cylinder is located between the piston rod body and the cylinder shell. A stop ring is fixed to or integrally formed on the peripheral face of the cylinder, and comprises at least three discrete active shape matching stop portions, a plurality of shape matching stationing portions, continuous type actuation mechanisms and reset mechanisms, wherein the shape matching stop portions are arranged in stop holes in the circumferential wall of the stop ring, all the shape matching stop portions can move between the retraction position and the extension position, the shape matching stationing portions are arranged on the inner circumference of the cylinder shell in the longitudinal direction at certain intervals, the continuous type actuation mechanisms are arranged at the bottoms of the shape matching stop portions, and the reset mechanisms are arranged in cavities between the shape matching stop portions and the stop holes. The mechanical stop mechanism can be used for the cylindrical linear actuator and can be safely and mechanically stopped in the specific discrete position.