To study the effect of soybean peptides (SBP) on sleep in Drosophila, SBP was prepared by proteolytic separation of soybean. 20 days-old male Drosophilas melangogaster were selected and divided into 4 groups. The basic medium was used as a blank control group, and three experimental groups were cultured using basic medium containing 2,4 and 8mg/mL SBP, respectively. The sleep duration was detected by the VideoTrack animal behavior analysis system, and the effects of SBP on circadian clock genes (per, tim, clk, cyc) of Drosophila brain, sleep related genes of rate-limiting enzymes of neurotransmitter synthetase (gad, tph, gdh, hdc), and serotonin (5-HT) were analyzed. The results showed that SBP had the best effect on prolongation of sleep in a dose dependent manner on the second day of sleep monitoring. By stripping the head, the circadian clock genes (per, tim, clk, cyc) and neurotransmitter synthetase genes (gad, tph, gdh, hdc) were analyzed. It was found that SBP administration prolonged the sleep duration of Drosophila melanogaster by up-regulating the levels of tim and tph and increasing the secretion of 5-HT in the brain.