The invention relates to an electric cylinder with a buffer. The electric cylinder is composed of a lead screw integrated with a motor rotor, an angular contact ball bearing, a first annular thrust cushion block, a second annular thrust cushion block, a long bolt, an electric cylinder upper barrel, a motor stator, a spline, an encoder, an end cover, a thread ball, a nut barrel, a check ring, an electric cylinder body, a piston ring, a buffer inner barrel, a buffer outer barrel, a sealing washer, a baffle ring, an annular cushion block, a rigid spring and a bracket. The motor rotor is integrated with the lead screw, the lead screw serves as the motor stator end to be supported to the interior of the electric cylinder upper barrel through the angular contact ball bearing, and extends into the electric cylinder upper barrel to be matched with the motor stator to form a motor, and the first annular thrust cushion block and the second annular thrust cushion block are installed at the two ends of the motor stator respectively; the threaded end of the lead screw and the nut barrel form an electric cylinder transmission device through the thread ball, and the electric cylinder transmission device is contained in the nut barrel and the electric cylinder body. The instant impact load effect of the electric cylinder in the starting process, the impact process and the like is reduced, and the service life of the electric cylinder is effectively prolonged.