The mode field distributing of photonic crystal fiber is measured,the coherence stripe of the beam from photonic crystal fiber is obtained,which is also analyzed in theory,the result of experimentation are closely matched with those of theory.the coherence reinforcement of several bunch light using adjustable structure of photonic crystal fiber are proposed,these are basic for the application of multi-core or multi-bunch photonic crystal fiber in high-power laser,amplifier and transmitting energy fiber.