A checking system with single optical fiber was established, which was mainly constituted of a light circulator and a optical film reflecting checking laser and transfering ignition laser between initiators and optical linker.Results show that the system can check the light path continuity of laser ignited initiators without changing the structure of laser ignited initiator.The reflected checking laser current is up to 200-300 μA when light path is perfectly continuous, which is only 30 μA when the light path is not continuous, and the laser energy transfer efficiency is approximatively quadratic function with the reflected checking laser current.