Abstract: Aiming at the disadvantages of small detection range of traditional level meter based on ray detector, the paper proposed a design scheme of level meter with wide range based on multi-counter, introduced detecting principle of the level meter and mathematic relation between ray counting and measured liquid level. It also gave design circuit of detector in the level meter,and calibration process of multicounter. The level meter was composed of many serial counters which made range effectively accepting ray of detector enlarge and detecting range could achieve 3 m.The level meter achieved range and measurement precision that other measurement modes were difficult to realize.