A lawn mower, wherein the cutter system of the lawn mower needs to judge whether the start pulse and the start signal of the cutter switch are valid at the same time under the condition that the seat switch is closed, and the cutter system will be started, only the two conditions are met at the same time, thus not only improving the safety when the cutter system is started, but also the startup of the cutter system can be completed automatically, saving time and labor, and reducing the operator's operation difficulty.