Chlorine trifluoride oxide (ClF₃O) has stronger corrosive and oxidizing properties than other chlorine fluorides such as ClF₃. It can react with numerous materials, e.g., water and hydrocarbons. The reaction between ClF₃O and organic hydrocarbons may occur at quite a low temperatures and cause an explosion. So far, however, no detailed information about the reactions is available. Using an intensified charge-coupled device (ICCD) system, transient emission spectra of the reaction of ClF₃O and n-decane were measured in a spectral range of 200~850 nm. Using density functional theory (DFT) method were performed to investigate the reaction mechanism of ClF₃O and n-decane. All calculated results are consistent with the experimental data, which indicates that the present results are credible. The emission spectra of CH and C₂ radical intermediates were observed in the reactions of ClF₃O and n-decane under a no-oxygen environment, and this shows that ClF₃O is a highly reactive compound. The detection of the CH, C₂ and OH radical intermediates shows clearly that a large amount of energy was released during the reaction between ClF₃O and n-decane under an oxygen environment. The primary peak was found at 431 nm corresponding to theA²Δ-X²Π electronic transition of the CH radical. The peak at 516 nm produced by theA³П_g-X³П_u electronic transition of the C₂ radical was also observed. The peak at 309 nm corresponds to theA²Σ⁺-X²П_i electronic transition of the OH radical was also found. The results of the calculations showed that the F atom on ClF₃O attacks the H atom on n-decane to initialize the reactions, and a F atom on ClF₃O abstracted h atom on n-decane to produce HF. The initial reactions were considered to be barrier-less reactions and extremely exothermic. Under a no-oxygen environment, a fluorination reaction occurred between ClF₃O and n-decane, and the products were ClFO, HF and corresponding fluoroalkanes. Fluoroalkanes may undergo dehydrogenation to form C₁₀H₂₀F. Then it is cleaved into C₄H₉ and C₆H₁₁F, then C₄H₉ further decomposed into C₂H₅ and C₂H₄, and finally formed CH and C₂ radical. The initial steps of reaction in the aerobic environment were the same as in an anaerobic condition. When the reaction proceeded to a certain degree, after producing alkane radicals, O₂ formed peroxic radicals, and peroxic radicals continue to decompose to form CH, C₂ and OH radical intermediates. In the presence of oxygen, many OH radicals were produced in the reaction process, which accelerated the process of reaction. Macroscopically, n-decane was initiated by deflagration and combustion. Results show that the main emission bands are attributed to OH, CH and C₂ radicals produced during the reaction process of ClF₃O and n-decane, which reveals that small OH, CH and C₂ radicals are important intermediate products in the reaction process of ClF₃O and n-decane. This is very important for understanding the micro-process of reaction of ClF₃O and n-decane. It also play an important theoretical foundation for the application of the weapon of ClF₃O.