The utility model relates to a cutting tool for a lawn mower, which comprises a main body and two main blades, each of which is arranged in opposite directions and connected to two opposite sides of the main body, each of which is respectively provided with a curved blade and a concave arc back, the curved blade is facing the plant to be cut, and the concave arc back is located on the opposite side of the curved blade.Thus, when the cutter is rotating at high speed, the structure of the arc bending blade and the concave arc back can effectively reduce the air resistance, so as to improve the stability of the cutter, and when the cutter collides with the stone, the arc bending blade and the concave arc back can effectively reduce each other's impact force, so as to increase the use safety and prolong the service life of the cutter.一種用於割草機的刀具，其包含有一本體及二主刀翼，各主刀翼彼此反向設置且分別連接於本體的兩相對側，各主刀翼分別具有一彎弧刀刃及一凹弧刀背，彎弧刀刃面向於待切割之植物，凹弧刀背位於該彎弧刀刃的相對側。藉此，當本創作之刀具在高速旋轉時，彎弧刀刃及凹弧刀背的結構將可有效地降低氣阻，以提升刀具的穩定性，又當刀具碰撞到石頭時，弧狀的彎弧刀刃及凹弧刀背能有效減少彼此的衝擊力，以增加使用安全性並延長刀具的壽命。
