To　study　the　regional　air　pollution　and　its　causes　of　pollution,　a　serious　heavy　air　pollution　process　was　analyzed　and　simulated.　Results　show　that　pollutants　cumulate　for　a　long　time　and　form　heavy　pollution　with　the　high　pressure　and　low　weak　pressure　in　the　air,　and　regional　air　quality　turns　good　in　the　influence　of　front.　A　meso-scale　meteorology　model　is　used　to　simulate　relative　meteorological　factors.　Simulation　results　can　explain　the　mechanism　of　heavy　pollution　in　northern　parts　of　China.