Abstract: In laser measurement system for coal stockpile,measurement of flight time is a key factor influencing on precision of the system.The paper designed a laser flight time interval measurement system used in laser measurement system for coal stockpile based on high precision measurement chip TDC-GP2 for time interal,introduced principle of laser ranging of TDC-GP2,and gave design of hardware and software of the system.Experimental result showed that the system has simple construction,high precision,and higher feasibility.