The invention relates to a coking wastewater treatment method and a system, belongs to the technical field of wastewater treatment and in particular relates to the coking wastewater treatment method which comprises the following steps: performing pretreatment, namely performing oil-water separation on wastewater, and performing an oxidation decomposition reaction on the separated wastewater; performing biochemical treatment, namely performing biological decomposition on the wastewater after the pretreatment step, wherein biological decomposition is repeated twice; and performing deep treatment, namely performing a flocculation reaction on the wastewater after the biochemical treatment, and performing a Fenton reaction on the wastewater after the flocculation reaction. The invention furtherrelates to a coking wastewater treatment system which uses the coking wastewater treatment method and comprises a pretreatment system, a biochemical treatment system and a deep treatment system in sequential communication. By adopting the method and the system, concentrations of refractory organic matters can be reduced or molecular structures of the refractory organic matters can be changed before the biochemical treatment system, the biodegradability of the coking wastewater can be improved, and the effluent quality after wastewater treatment can be ensured.