The splice losses of photonic crystal fibers (PCFs) are theoretically and experimentally studied. For the two same PCFs with the triangular lattice, the splice losses are theoretically investigated by using finite element method (FEM) with perfectly matched layer (PML). The results show that the fundamental mode field mismatch induces the rotation losses with rotating one of the two PCFs when two optical axes are coincident. The rotation losses oscillate with increasing rotation angle, and the pitch between two nearest air holes has greater impact on the rotation losses than the air hole diameter. Optimizing the parameters of the arc fiber splicer, avoiding the air hole collapse and bubble generation, the rotation losses are experimentally investigated for two same PCFs. The measured rotation loss is coincident with the simulation results. Experiments can further reduce the splice losses of PCFs.