In order to detect the existence of contaminants in inner surface of the transparent vessel, an optical low coherence interference measurement system based on the reflection of the inner surface of the vessel is established. Broadband low coherence laser diode light source and improved Michelson interferometer are adopted. The optical path of the measuring arm is aligned with the transparent vessel, and then optical path of the reference arm is adjusted. When the optical path from the wall of the inner surface in the vessel is equal to the optical path from the reference arm, there is interference. The dynamic interference signal can be captured and recorded. The signal is processed and extracted by using MATLAB software. According to the difference of the intensity of the interference signal, we can distinguish whether there is contaminant in the transparent vessel. This paper can provide a real-time and novel method for detecting contaminants in the transparent vessels in biomedical, food and other fields.