The invention relates to a cylinder supporting tool which comprises a bracket, a first supporting arm and a second supporting arm, wherein the first supporting arm and the second supporting arm are relatively arranged in a left-and-right direction. A V-shaped trough for placing a cylinder is formed between the first supporting arm and the second supporting arm. The first supporting arm and the second supporting arm are rotatably connected with the bracket through hinging shafts so that the first supporting arm and the second supporting arm rotate in a vertical surface. The first supporting arm and the second supporting arm are provided with angle adjusting structure for adjusting rotation angles of the first supporting arm and the second supporting arm. The bracket is provided with a position keeping mechanism for keeping the first supporting arm and the second supporting arm to preset positions. According to the cylinder supporting tool, the included angle of the V-shaped trough is changed through rotating the first supporting arm and the second supporting arm so that one cylinder supporting tool can stably support the cylinders with different diameters; furthermore a purpose of height adjustment can be realized through adjusting the rotation angles of the first supporting arm and the second supporting arm, thereby ensuring a fact that the centers of the cylinders with different diameters are at the same height.