Air source heat pump defrosting method and system

The invention relates to an air source heat pump defrosting method and system, the melting point of ice can be reduced by using a salt solution, so that frost condensed on the surface of a heat exchanger can be quickly melted, a coil of the heat exchanger is defrosted by using the characteristics that the salt solution is not easy to freeze and does not cause pipeline blockage, and the salt solution is electrolyzed after primary defrosting, so that the heat exchange efficiency is improved. After electrolysis, the salt solution is continuously used for defrosting, so that the reutilization of the electrolyte is realized, the waste of the salt solution is avoided, meanwhile, the energy waste caused by defrosting by reverse refrigeration of the air conditioning unit is avoided, and the defrosting of the air source heat pump under the non-stop condition is realized. Besides, in the process of electrolyzing the salt solution, salt does not participate in the electrolytic reaction, so that the electrolyzed water is