Sodium dichloroisocyanurate was replaced by sodium hypochlorite as the oxidant for improving the synthetic method of 4, 4′-azobis (1, 2, 4-triazole). Three different factors, the illumination time, the molar ratio available chlorine to acetic acid and the reaction temperature, were studied for the influence of the reaction process. The structure and properties of the product obtained were compared with literature ones. Results show that under the condition of dark (0h illumination time), the molar ratio available chlorine to acetic acid 1:2.5 and 7 ℃, the yield is 78%. Compared with sodium dichloroisocyanurate, sodium hypochlorite used as the oxidizing agent to synthesize 4, 4′-azobis(1, 2, 4-triazole) can not only omit the separation and purification of 4, 4′-azobis(1, 2, 4-triazole), but also solve the problem of processing the isocyanuric acid.