Low-smoke density plastic composition and its preparation method and use

The invention discloses a low-smoke density plastic composition and its preparation method and use. The low-smoke density plastic composition comprises a smoke-inhibition agent. The smoke-inhibition agent comprises at least one inorganic sulfur-containing compound containing sulfur atoms having positive four or more valences, and the at least one inorganic sulfur-containing compound is not a nonmetal sulfate or a nonmetal bisulfate. In combustion, the low-smoke density plastic composition has low smoke density and has a low carbon monoxide release ratio. The inorganic sulfur-containing compound as the smoke-inhibition agent is used for preparation of low-smoke density plastic. A lot of experiments prove that the at least one smoke-inhibition agent can produce obvious effects of inhibiting smoke and reducing a CO ratio, is not limited by a plastic system, can be used for different types of plastics, and has a wider use range than that of the existing smoke-inhibition agent.