In order to screen the best photoperiod to promote the quality of Talinum crassifolium (Jacq.) Gaertn., we conducted pot experiment to study the influence of different photoperiods on the growth and quality of T. crassifolium, as well as the changes of physiological characteristics during the flowering process. The results showed that： (1) the extension of photoperiod was not only beneficial to the growth of T. crassifolium, but also promoted the formation of its nutritional quality. (2) Under the photoperiod of 14 h/10 h (Day/night), the plant height, stem diameter, root length, leaf area and dry and fresh weight of shoots in T. crassifolium were better than other treatments, and the growth was the best. The contents of cellulose, V_C, oleanolic acid, flavonoids, total phenol and free amino acid in T. crassifolium were the highest. (3) The contents of soluble sugar, soluble protein and Ca in T. crassifolium leaves increased at first and then decreased at 14 h/10 h photoperiod. In conclusion, 14 h/10 h photoperiod was the best for the growth and quality of T. crassifolium and its flowering process may be related to the metabolism of soluble sugar, soluble protein and Ca.