Connecting device of linear drive includes a main body part with a rectangular profile, and a hardware stamping. The two opposite sides of the main body part are respectively fixedly connected with the hardware stamping. The middle portion of the main body part has a hollow cavity. A threaded axle hole device with threaded holes inside is accommodated in and fixedly connected with the cavity. The lateral walls of the cavity have locating grooves. The hardware stamping includes two reverse bends between which the portion is disposed above the main body part. The lower portion of the hardware stamping is tightly adhered to the lateral side of the main body and bolted, while the upper portion of the hardware stamping has a connecting hole. The connecting device is light in structure, small in size and more convenient to install and is improved in bearing capability and operation stability.