The invention relates to the technical field of foaming materials and provides a styrene-butadiene rubber/natural rubber/negative oxygen ion powder blended closed-pore secondary foaming material and a preparation method thereof.The negative oxygen ion powder of the styrene-butadiene rubber/natural rubber/negative oxygen ion powder blended closed-pore secondary foaming material can also effectively combine with a styrene-butadiene rubber raw material and natural rubber under the condition that the high biological activity is kept, the dispersion of the negative oxygen ion powder on rubber molecules is effectively improved, the original excellent physical properties of the rubber can be effectively kept, and sufficient negative oxygen ions can be also effectively and fully released.The concentration of the negative oxygen ions continuously released by a finished product prepared by the foaming material can be up to 1500 per cubic centimeter in a static state, the concentration of the continuously released negative oxygen ions can be up to 8000 per cubic centimeter in a dynamic state, the ambient air quality can be improved, the foaming material is beneficial to human body health, and the preparation method of the foaming material is simple in operation, easy to achieve and suitable for large-scale production and usage.