The invention relates to a cooling device of a sewing machine. The cooling device is provided with air supply units arranged around an opening part of the sewing machine and used for supplying air to cooling objects in the sewing machine, a first filter part arranged on an air sucking side of the air supply unit, a second filter part arranged on an air discharging side. The first filter part is detachable relative to the air supply unit through a first clamping mechanism. The second filter part is detachable relative to the opening part through a second clamping mechanism. The first filter part and the second filter part are detached from the air supply unit by operating personnel, so the first filter part and the second filter part are checked and cleaned easily.