The principle of phasic laser range was introduced.The principle and the safety of optical fiber sensor based on phasic laser range were analyzed and researched.Optical system based on this principle was designed.The part of laser-receiving experiment was done by building experimental platform.Experimental results show that the system can work well and achieve the scale precision of laser range finder.The sensor enable electrical system to keep away from the measuring scene

so as to achieve the intrinsical safety requirements.