Abstract: In order to analyze the reason of Trichosanthes kirilowii seed oil solidification, find out the molecular structure of Trichosanthes kirilowii seed oil viscosity changes. Using Perilla seed oil as a reference, ultraviolet spectrophotometry was performed in Perilla seed oil and Trichosanthes kirilowii Maxim. After the UV scan and analysis, maleic acid and conjugated linoleic acid as an isolated double bond and two conjugated double bonds as standard draw standard curve were compared, analyzed the difference of unsaturated conjugated double bond type and the different content of fatty acids contained were analyzed in Trichosanthes kirilowii seed oil and Perilla seed oil. The results showed that: Perilla seed oil unsaturated fatty acid contains only isolated double bond in a concentration of 365.8 mg/mL, while the snakegourd fruit seed oil unsaturated fatty acid contains not only isolated double bond, but three conjugated double bonds. In addition, the yellow TKM seed oil also contains two conjugated double bonds (the content was 197.01 mg/mL). Trichosanthes kirilowii seed oil contained a certain amount of two conjugated double bond or three conjugated double bond in unsaturated fatty acid, which increased the possibility of the addition and the polymerization reaction, resulting in an increase of the content of saturated fatty acids, a decrease of the freezing point and an increase in viscosity, which was the main reason prone to the easily solidification during the storage of Chinese Trichosanthes oil.