In order to test the content and distribution of elements, a multispectral imaging system is presented in the paper. The liquid crystal tunable filters (LCTFs) are placed into an ordinary optical imaging system as the spectrum-dividing component. The spectrum resolution of the system is up to 0.5 nm, and the spatial resolution depends on the LCTFs, CCD camera and the lenses. The software was also designed to control the data capturing, data processing and data showing. The transmission rate and linear working range of the device were measured for getting the character spectrum of the sample. To research the spectrum stability of the device, the spectrum of standard lamps were tested. A piece of coptis which is a kind of traditional Chinese medicine was tested as an experiment. The results show that both the content and the distribution of the main element of the coptis can be got in-vivo. The device is useful in many fields such as biology, life sciences, etc.