Objective To analyze the effects of Procambarus clarkii shell bioactive peptides (PCSBP) on the growth performance, muscle antioxidant capacity, and circadian rhythm related gene expression of Pelodiscus sinensis.Methods In this experiment, different concentrations (0.05%, 0.10%, 0.20%, and 0.50%) of PCSBP are added to the diets of P. sinensis for 70 days. The growth performance, muscle antioxidant capacity, and expression levels of circadian rhythm related genes are measured to preliminarily explore the regulatory effect of PCSBP on the muscle antioxidant capacity and circadian rhythm of P. sinensis.Results With the increase of PCSBP concentration in diets, the final body weight, weight gain rate, and specific growth rate of P. sinensis show a significant upward trend, and the feed conversion rate decreases. The activities of total superoxide dismutase (T-SOD), catalase (CAT), and glutathione peroxidase (GSH-PX) in the muscle of P. sinensis show a significant increase trend with the increase of PCSBP concentration. Meanwhile, PCSBP significantly up-regulates the expression of nrf2 and keap1, key signaling molecules for antioxidant capacity and activates the expression of antioxidant enzyme genes sod1, sod2, cat, gpx1, gpx2, gpx4, gstk1, and gstz1. In addition, PCSBP significantly regulates the expression of circadian rhythm core genes bmal1, clock, nr1d2, per1, per2, cry1, cry2, and npas2. There is a significant correlation between the antioxidant signaling pathway of nrf2-keap1 mediated by PCSBP and the expression of core genes of circadian rhythm. It is significantly positively correlated with the expression of bmal1, clock, per2, cry1, cry2, and aanat, while significantly negatively correlated with the expression of npas2, rora, and rorc.Conclusion PCSBP has a regulatory effect on the antioxidant capacity and circadian rhythm of P. sinensis, effectively enhancing the body’s oxidative stress resistance.