A cationic lipid compound, and a preparation method therefor and use thereof are provided. The cationic lipid compound features a hydroxyl group at the head part, and its overall structure resembles a cone with a small head and a large tail. The LNPs prepared using the cationic lipid compounds with the aforementioned optimal structure usually exhibit enhanced biocompatibility and higher in vivo mRNA transfection efficiency, achieving unexpected technical effects. The synthesis route of the cationic lipid compounds is straightforward and practicable, with inexpensive and readily available raw materials, facilitating industrial production. Furthermore, the LNPs produced from the cationic lipid compounds possess a stable nanostructure that can be stored at low temperatures for a long time, thereby prolonging the shelf life of the pharmaceutical products while reducing the transportation requirements.