Micro-liquid distribution operation has been a core part of the fully automatic liquid handling platform in clinical testing. Accurate and fast automatic detection of liquid level with disposable tip is the precondition to ensure the stability of the whole operation of liquid handling platform. By further research on the liquid level sensing technology of pressure sensor, in this paper we designed a new type of accurate and stable micro-liquid level detection system and verified its stability, instantaneity and accuracy by setting up a small reagent distribution platform. It was shown that the liquid level detection system designed in this paper has reliable stability, good instantaneity and high accuracy, with the liquid level detecting accuracy up to 100%, the response speed after detecting the liquid level reaching millisecond and the depth in the liquid level less than 0.3 mm. Besides, there is no limit on the physical and chemical properties of the liquids to be tested, which is consistent with the technical indicators of the liquid handling platform.