The invention discloses a method for combined treatment of wastewater of a phenol-containing gas by an ozone flocculant. The method is characterized by comprising the following steps of: (1) oxidization treatment, namely carrying out oxidization treatment on synthetic natural gas (SNG) waste water by using ozone; (2) carrying out primary intermediate reservoir treatment; (3) carrying out flocculation dosing treatment, and feeding a compound agent containing aluminum; (4) carrying out precipitation reaction treatment; (5) carrying out secondary intermediate reservoir treatment; and (6) processing by a biological response processor, namely feeding the water from a secondary intermediate reservoir to a biological reaction tank, wherein the standing time of the biological response processor is 4-20 hours; processed water is recycled; biological sludge is domesticated by bottom mud of a sewage pool at scene; bacteria Bacuillus sp.JY01 capable of degrading phenol is added; the gene registration number is EU798946.