The invention relates to a serging device of a ribbon loom, in particular to a serging device of a heavy ribbon loom. The serging device comprises a main drive mechanism and a rotary shuttle drive mechanism, wherein the main drive mechanism is driven in a chain drive mode, one end of the main drive mechanism is coaxially connected with a main shaft, and the other end of the main drive mechanism is connected with the rotary shuttle drive mechanism by a drive gear; and the rotary shuttle drive mechanism is driven in a gear drive mode. The serging device provided by the invention has the advantages that a rotary shuttle is used to hook a selvage, therefore, the serging device is suitable for the heavy shuttleless ribbon loom; and band edges woven by using the serging device in the invention are smooth, firm and starched, and can prevent edge warps from loosing and falling off and increase the resistance capability of the edge part of a heavy hanging strip to external forces.