The growth kinetics of PNP degradation by Rhodobacter sphaeroides H strain was analyzed by fitting the Haldane kinetic equation. The effects of nutrition factors (carbon source, metal ions and NaCl concentration) on the degradation of PNP by H strain and the substrate broad spectrum of phenol by H strain were investigated, and the metabolic mechanism of degradation of PNP by H strain was speculated. Results show that the growth kinetics of H strain degrading PNP conforms to Haldane model (R²=0.9990). The most suitable carbon source and metal ions for degrading PNP by strain H are malic acid and Ca²⁺, respectively, and the tolerance value of NaCl concentration is 20 mg·L^-1. Influence of the catechol on PNP degradation is the greatest among phenols. High performance liquid chromatography-mass spectrometry (HPLC-MC) was used to analyze the metabolites of PNP produced by the strain. It is found that the intermediate products are mainly hydroquinone (HQ), 4-hydroxymuconic acid semialdehyde (4-HS) and maleamic acid (MA). Meanwhile, enzyme activity analysis shows that the substrate HQ produces 4-HS under the action of hydroquinone 1,2-dioxygenase in crude enzyme solution, thus suggesting that strain H may utilize the metabolic pathway of hydroquinone.