The muti-core photonic crystal fibers (MCPCF) is one major research direction to realize high power supercontinuum, and a key problem to realize all-fiber is how to solve the low loss fusion splicing for MCPCF. One method to realize low loss fusion splicing for seven-core PCF by selected air hole collapse technique is introduced. Mode field property and its effect on splicing loss both before and after process are numerically simulated. Selected air hole collapse is achieved for a seven-core PCF experimentally and a low loss (0.22 dB) is realized for splicing to a double cladding fiber with core diameter of 15 μm.