The following phenomena were captured in combustion process by high-speed microscopic camera technology: the periodic expansion/fracture of micro bubbles in aviation kerosene RP-3 suspended droplet. The phenomena that the micro bubbles sharply expanded and suddenly fractured were found inside the burning 1.25mm diameter droplet at environment temperature of 973K. Namely: (1) in 0.04s

the diameter of the micro bubbles increased by 41.6%; (2) in 0.01s

the expansion bubble was fractured inside the droplet

which stimulated the droplet's sharply oscillations; (3) the droplet resumed relatively stable evaporation and combustion，and the internal residuals of the micro bubbles were observed to start the second round of expansion/fracture; (4) the droplet burned away after three rounds of expansion/fracture. The following mechanism was speculated: the quartz fiber heated by high temperature induced the rapid evaporation effect inside the droplet

which was the driving force of the micro bubble periodic expansion/fracture. Moreover

surface tension was the restraint mechanism to restore and maintain the droplet stable combustion.