Based on the supercell overlapping method, the full vector model is adopted to compute the mode field radius of photonic crystal fibers (PCF). And then, the splice losses of PCF-single model fiber (SMF) under the influence of transverse offset, angular misalignment and mode field mismatch are analyzed, respectively. The theoretical values of PCF-SMF-28 in some conventional ranges of structural parameters {Λ, d/Λ} are offered, and the effect of each structure parameter on the splice loss is discussed. The splice loss between two PCFs with different structures is analyzed in brief. It is concluded that the splice loss is very sensitive to transverse offset and angular misalignment, the most important structural parameter effecting splice loss is the pitch, Λ, of PCF, the splice loss of PCF-SMF is relatively low if the pitch of PCF is larger than the radius of SMF core, and the splice loss between two PCFs with different structures is mainly decided by the difference between their pitches.