The invention relates to the technical field of mechanical equipment, and discloses a mowing machine with the height convenient to adjust. The mowing machine with the height convenient to adjust comprises an equipment body, wherein the inner bottom wall of the equipment body is fixedly connected with a motor; an output end of the motor is fixedly connected with a transmission shaft; one end, which is away from the motor, of the transmission shaft penetrates through the equipment body and extends out of the equipment body; and one end, which is positioned outside the equipment body, of the transmission shaft is fixedly connected with a blade. According to the mowing machine with the height convenient to adjust, by a supporting plate, sliding blocks can slide to two sides under the effect of a connecting rod; under the condition of stress, a spring drives the supporting plate to reset with the aid of elasticity of the spring, and therefore, the damping effect is achieved; the mowing machine can run on various bumpy groups; under the effect of a gear, the height of a brace can be adjusted by rotation of an adjusting handle, therefore, the height of the mowing machine can be adjusted according to heights of grasses required to be trimmed, and meanwhile, the circumstances that the mowing machine collides with some invisible barriers and then the blades are damaged are avoided.