Small-area composite ventilation and dust removal fresh air device, heading machine and construction method

The invention provides a small-area composite ventilation dust removal fresh air device, a heading machine and a construction method. The small-area composite ventilation dust removal fresh air device comprises a fresh air system and a dust removal system. The fresh air system comprises a fresh air distributor; the dust removal system comprises a dust remover, a top dust suction shield and side dust suction shields located on the two sides of the top dust suction shield. A fresh air environment operation space is defined by the fresh air distributor, the top dust suction shield and the side dust suction shield. One ends of the top dust collection shield and the side dust collection shield are dust collection ports, and air outlets at the other ends of the top dust collection shield and the side dust collection shield are connected with an air inlet of the dust remover; a plurality of air outlets are formed in the fresh air distributor and face the operation space; a dust suction port of the top dust suction s