In recent years, with the development of liquid crystal display (LCD) technology, the multi-primary colors LCD technology is the major trend in the future. The disadvantages of the three primary colors LCD and the solutions of multi-primary colors are increasingly mentioned, and the displays of four primary colors LCD have come to the market. Five primary colors display technology has been proposed, but less about research and literature of it. Adding cyan primary color of 505 nm and yellow primary color of 580 nm based on original three primary colors such as red, green and blue (RGB) can make five primary colors LCD and LCD color gamut is enlarged. Multi-primary colors display will be the trend of future display industry. A spectrophotometer is used to test the electro-optical characteristics of positive TN-LCD five primary colors under different driving voltage to analyze the threshold characteristics of five primary colors, which provides references for the choosing of the driving parameters of multi-primary colors LCD display technology.