Coal chemical wastewater contains a large number of difficult-to-degrade organic matter, including phenols and highly toxic substances, which pose a serious threat to the environment. Therefore, the use of economical and reasonable means of treatment to purify coal chemical wastewater has been a hot research direction for resource recycling. Four common organic substances in coal chemical wastewater, namely, phenol, p-cresol, hydroquinone, and quinoline were selected to simulate coal chemical wastewater. To study the effect of irradiation technology on the theoretical biochemistry of wastewater samples, these were treated by ionizing irradiation technology and catalytic oxidation using hydrogen peroxide; this was combined by the study of the physicochemical properties of the samples before and after treatment, such as chemical oxygen demand (COD) and 5-day biological oxygen demand (BOD₅). The effect of irradiation technology on the theoretical biochemistry of wastewater samples was investigated. The results showed that γ irradiation generated highly active free radicals through the irradiation of water, and the free radicals in turn generated inorganic carbon sources or microbially available organic matter by interacting with the non-degradable organic matter in the wastewater, improving the mineralization and biochemistry of coal chemical wastewater. The BOD₅/COD (B/C) value of the non-degradable organic wastewater with an initial concentration of 80 mg/L increased from 0.044 to a maximum of 0.310, which was within the range of biodegradation. The addition of H₂O₂ with the same concentration could increase the B/C value to a maximum of 0.466, improving the biodegradability of the non-degradable material. The response surface parameter optimization experiments were conducted by monitoring the H₂O₂ concentration, pH, and absorbed dose as three factors. The results showed that the error between model predictions and actual measured results was no more than 5%. The optimal γ irradiation treatment conditions that improved the biochemistry of wastewater were obtained experimentally by setting H₂O₂ concentration to 21.9 mmol/L, pH to 7.4, and absorbed dose to 19.6 kGy.