The boiler collaborative treatment technology of coking solid waste realizes the heat resource recovery. The CO combustion test of raw coal, biochemical sludge and tar pulverized coal was carried out on a 480 t/h pulverized coal boiler to evaluate the environmental harm of the collaborative utilization of coking solid waste. The flue gas, slag, fly ash and ammonium sulfate were sampled and analyzed to study the emission characteristics of various pollutants and their impact on the environment under the mixed combustion condition. The results show that the combustion is stable and the fluctuation of various operating parameters is small when the mixing ratio of coal, biochemical sludge and tar pulverized coal is 100.0∶3.0∶1.5. Naphthalene and acenaphthylene in low ring (2-3 ring) polycyclic aromatic hydrocarbons are the main components of 16 PAHs, and the monomer contents of other PAHs are low. The total toxic equivalent concentration of PAHs in flue gas is 71.3 ng/m3, and the concentration of PAHs in solid samples is lower than 0.5 mg/kg. The concentration of dioxins in flue gas is 0.004 3 ng/m3, which is 61.3% lower than that in blank condition. The concentration of dioxins in solid samples are lower than 2.0 ng/kg. All organic matter emissions under collaborative working condition meet the standards. The mass ratio of Cr and As in biochemical sludge are 3.6 and 26 times of that in raw coal, resulting in the mass ratio of Cr and As in mixed fuel increased by 21.1% and 63.1%, respectively, and other heavy metals do not increase significantly. More than 90% of Cr and As exist in fly ash, about 2%-4% in slag, and only a small part in flue gas and ammonium sulfate. The Cr content in flue gas is 6.69 μg/m3, which decreases by 45.2% compared with blank condition, and the As content is below the detection limit. The leaching experiment of solid samples such as slag, fly ash and ammonium sulfate show that the leaching mass concentrations of Cr and As in solid samples are lower than 4 mg/L and 0.1 mg/L, respectively and there is no environmental risk in the leaching of heavy metals. The emission concentrations of pollutants in the test process are lower than the current standard limit in China, and the environmental risk of boiler collaborative treatment technology is controllable, which provides a reference for the harmless utilization of coking solid waste.