The invention relates to a treatment system and treatment method for fracturing flow-back fluids of oil fields and gas fields, wherein the treatment system comprises a dosing stirring system, an electrochemical treatment tank, a settlement system, an air floatation system and a filtration system, wherein the dosing stirring system is used for mixing and stirring an alkalinizing agent, a coagulant and a coagulant aid with the fracturing flow-back fluid to be treated respectively and then sending to the electrochemical treatment tank, the fracturing flow-back fluid treated by the electrochemical treatment tank is sent to the settlement system to separate, and the separated fracturing flow-back fluid is sent to the air floatation system, and then reused or reinjected after being filtered by the filtration system. The treatment method for the fracturing flow-back fluids of the oil fields and gas fields solves the technical problem that the conventional treatment method of the fracturing flow-back fluid can only perform field treatment, and the treatment process for the fracturing flow-back fluid disclosed by the invention is reasonable in design, and the treatment system of the fracturing flow-back fluid is mainly designed into skid-mounted equipment and adopts vehicle-mounted transportation, thereby being mobile and flexible.