Abstract: Objective To understand the process of producing productive dust during the operation of the coking unit in a coking plant in Golmud，evaluate the effect of dust prevention measures，and analyze the risk degree of productive dust in the operation process of coking unit. Methods In June 2021，the occupational health field investigation was carried out in a coking plantin Golmud of Qinghai Province，and the productive dust was sampled and tested in laboratory to analyze the harm degree of exposure to productive dust at different posts. Results The coking unit in Golmud produced coal dust and coke dust in the link of coal preparation，coke making，coke quenching and coke line.The analysis showed that the free silica contents were less than 10%. The concentration of coal dust at coal preparation post was 5.216 mg/m³，and the that at pulverized mixing post was 11.252 mg/m³. The short-term exposure concentrations of dust in dust collector，coke cutter and coke release worker were more than five times of the long-term permissible contact concentration（>40 mg/m³）. The exposure to productive dust at the above posts exceeded the requirements of occupational exposure limits. The dust exposure level of dust-exposed post was in class Ⅱ-Ⅳ，and the dust operation was 0-Ⅱ level. Conclusions The working environment of cokingplant in Golmudis relatively bad，and some employees in the production link are directly exposed to the productive dust. It is necessary to pay attention to the maintenance of coking equipment in daily work，strengthenthe awareness of self-protection of employees，and improvethe management level of managers.

Key words: Coking unit, Productive dust, Exposure level, Job classification