The micro-explosion and combustion characteristics of n-butanol/n-pentanol/biodiesel blended fuel droplet cluster are investigated using high-speed backlit imaging technique. The droplet cluster includes 9 droplets with the same diameter, which are arranged in a 3 × 3 matrix equidistantly using the fiber support method. The results indicate that when the normalized droplet spacing (s/d0) is less than 3, the coalescence phenomenon caused by micro-explosions will occur between adjacent two or three droplets in the droplet cluster. For small s/d0 (2 ∼ 4.5), the droplet cluster sustains a fully enveloped flame. Within the range of s/d0 of 5 ∼ 7, two combustion modes emerge: transitioning from a fully enveloped flame to an independent flame, and merging independent flames into enveloped flames, eventually reverting to independent flames. At a s/d0 of 8, each droplet within the cluster maintains an independent flame. In addition, the combustion rate of droplets 1–3 and 7–9 reaches its maximum value at 4 ∼ 4.5 s/d0, about 30 % higher than single droplet. Most importantly, the droplet micro-explosion intensity at the center of the droplet cluster is higher than that of other droplets (similar to a single droplet), which is caused by the “group micro-explosion” effect.