The photo-oxidation caused by sunlight exposure has damaged the clear coat layer of the car. How to improve the anti-aging performance of the coating has become the focus of research. Adding hindered amine light stabilizer (HALS) to the clear coat paint is an important method to extend the life of the car clear coat. Therefore, a novel hindered amine light stabilizer (HALS) was designed and synthesized. Triphosgene and N-butylamino-2,2,6,6-tetramethylpiperidine were used as starting materials to obtain intermediate Ⅰ through nucleophilic substitution reaction, and then reacted with hexanediamine piperidine to generate intermediate Ⅱ, and finally hydrolyzed to obtain the target compound TM-3. The structure of TM-3 was confirmed by 1H NMR and 13C NMR. Its UV absorption performance, thermal stability, light stability and solubility were studied. The results show that the novel HALS TM-3 has strong absorption at 210nm; good thermal stability, it can maintain thermal stability below 400°C and can withstand higher temperatures; due to the introduction of hydrophilic hydroxyl group, it has better solubility in aqueous organic solvents than HALS 770; comparing TM-3 and HALS 770 in car clear coat paint, In terms of chromatic aberration, the sample with TM-3 added had a chromatic aberration of 6.01 after 800 h of simulated ultraviolet irradiation, while the sample with HALS 770 added had a chromatic aberration of 6.72; similarly, in terms of gloss loss rate, the sample with TM-3 added had a gloss loss rate of 4.6% after 800 h of simulated ultraviolet irradiation, while the sample with HALS 770 added had a gloss loss rate of 6.7%. It can be seen that TM-3 has better light stability than HALS 770. The novel hindered amine light stabilizer TM-3 has potential commercial application prospects in the aging resistance of car clear coat coating.