Abstract: A crimping structure of a small irregular can and a manufacturing method thereof, in particular to a seam method for buckling a bottom by stamping. The crimping structure includes a can body crimping edge and a can bottom crimping edge made of a plate material of a same type, wherein the can body crimping edge covers the can body crimping edge to crimp 90 degrees inward. A four-layer structure with a first can body crimping edge layer, a can bottom crimping edge layer, a second can body crimping edge layer and a can bottom layer, arranged in a sequence, is formed. By adopting the above-mentioned four-layer crimping structure of the small three-piece irregular can, the sealing performance of the can body is greatly enhanced, effectively improving the moisture-proof performance, thereby protecting the safety of food in the can.