Plunger load cylinder with travel end automatic protection function

The invention discloses a plunger load cylinder with a travel end automatic protection function and relates to the technical field of hydraulic cylinders. When a plunger rod moves to the travel end, pressure inside a cylinder block is fast reduced, the speed of the plunger rod is made to be reduced fast, and accordingly, the situation that the plunger rod flies out, and consequentially, quality accidents including damage to the load cylinder or even hurt to the personal safety are caused is avoided. The plunger load cylinder comprises the cylinder block and the plunger rod. The first end of the cylinder block is sealed, the second end of the cylinder block is provided with an opening, the first end of the plunger rod stretches into the cylinder block from the opening, the second end of theplunger rod is located outside the cylinder block, the outer wall of the plunger rod is in sealed and sliding connection with the opening, an unloading structure is arranged in the position, close tothe first end of the plun