Disclosed herein is a safety apparatus for a cultivator, wherein the driving cylinder includes a body wherein a rod having a pressurizing plate at a front end of the rod is inserted into the body; a first inlet hole and a second outlet hole which are formed at one side of the body; a first inlet hole and a second outlet hole which are formed and positioned at a rear portion of the pressurizing plate when the rod extends from the body; a first outlet hole and a second inlet hole which are formed at the other side of the body; a relief valve which is installed at the first outlet hole; a first hydraulic line which is employed to connect the relief valve and the first inlet hole; a second hydraulic line which is employed to connect the second outlet hole and the second inlet hole; and a check valve which is installed at any of the second outlet hole, the second inlet hole and the second hydraulic line so as to prevent the hydraulic pressure from being returning back to the second outlet hole.