Objective To study the effect of triptolide-loaded exosomes in prostate cancer model mice. Methods A mouse model of prostate cancer was established and three groups of mice were prepared: control, TPL and exo-TPL groups. The MTT method was used to observe inhibition of cell proliferation. qPCR was used to detect the expression of NF-_κB and p53. On the 8th , 11th , 15th and 18th day after model induction, mice were administered TPL or exo-TPL. The volume and mass of tumors were observed and the survival time was recorded. The blood concentration and tissue distribution of triptolide were observed in the different groups. Results Compared with the TPL group, the inhibition of RM-1 prostate cancer cell proliferation was significantly increased in the exo-TPL nanoparticle group. The mRNA level of NF-_κB was significantly decreased, while that of p53 was significantly increased. The tumor volume and mass in the exo-TPL nanoparticle group were significantly smaller than those in the TPL group, and the survival time was prolonged. Compared with the TPL group, the exo-TPL nanoparticle group maintained higher concentrations of triptolide in blood and tissue. Conclusions Compared with TPL treatment, exo-TPL was more effective at suppressing prostate cancer.