To explore the high efficiency catalyst of Fenton system under the condition of high pH，Fe²⁺，Fe³⁺ Co²⁺，Ni²⁺，Cu²⁺ and Zn²⁺ salts was selected to react with 1， 10-phenanthroline to prepare the corresponding metal complexes by mixing the 0.2 mol/L two components with the same volume，and then the catalytic activity of the complexes catalyzing H₂O₂ oxidative to degrade hydroxypropyl guar gum under high pH conditions was evaluated. The results showed that the six complexes all had certain catalytic effect of H₂O₂，and CuL was the best one，which performed good catalytic effect in the range of pH 7.0—14.0. Under the condition of 45℃，pH=10.0，with H₂O₂ amount of 10.0% to the mass of hydroxypropyl guar gum，and Fe（Ⅱ） L amount of 5.0% to the mass of H₂O₂，and degrading for 40 min，the relative viscosity of the hydroxypropyl guar gum system reduced from 14 to 1.2，close to the water’ s viscosity；the relative molecular weight was reduced from 2 million to 2864；the COD value was reduced from 22.49 g/L to 8.73 g/L. Increasing the amount of H₂O₂ to 25.0% of the mass of hydroxypropyl guar gum，the COD values could be reduced to 41 mg/L within 4 hours