The utility model discloses an auto-foam dilution system which comprises an automatic dilution part and an automatic foaming part. The automatic dilution part comprises a liquid pump. Two branch pipes are led from an inlet of the liquid pump to a water tank and a foamer tank respectively. A foamer flow pump is disposed on the connecting pipe between the foamer tank and the liquid pump. The automatic foaming part comprises a foam gun which is provided with an air inlet, a liquid inlet and a foam outlet. The air inlet is connected with a compressed air source pipe, and an air flow meter and an air regulating valve are disposed on the compressed air source pipe. The liquid inlet is connected with an outlet pipe of the liquid pump, and a liquid flow meter and a liquid regulating valve are disposed on the outlet pipe. The regulating valves can be accurately controlled in real time to regulate air and liquid flow by monitoring the corresponding flow meters with a computer. Therefore, qualified foam can be produced by the automatic foaming and dilution system. The automatic foaming and dilution system is applicable to foam preparation.