Abstract: This article mainly elaborates the current status of micro-fine minerals sorting, combined with the theoretical research progress of the flotation process of fine-grained minerals, it is pointed out that the key factor to improve the separation efficiency of fine-grained minerals is to strengthen the interaction process between mineral particles and bubbles.The mechanism of nano-bubble strengthening micro-particle mineral flotation was discussed based on the "nano-bubble bridge capillary force" generated by nano-bubble. the application of nano-bubble in micro-particle mineral flotation was introduced, the application value and development prospect of nano-bubble in micro-particle mineral flotation were prospected.