Owing to the widely applications of silver nanoparticles(AgNPs) in catalysis and biomedicine, researchers have focused their attentions on the formation method. In this work, a green and easy synthesis method of silver nanoparticles(AgNPs) by 254 nm ultraviolet lamp radiation using Cornus officinalis aqueous extract was reported, and the antioxidant, antibacterial and anticancer activities were assessed. The influence of the solution pH(7.0), material proportion(1∶1) and reaction time(1 h) on reduction reaction were discussed to confirm the most efficient reaction condition. X-ray diffraction(XRD), dynamic light scattering and transmission electron microscopy were conducted to investigate the shape, size and surface of the silver nanoparticles, revealing a face-centered cubic(fcc) structure and spherical shape with an average particle size of (55.4±0.9) nm covered by anion(Zeta potential: -10.2 mV). By calculating the free radical scavenging rate for DPPH, the antioxidant activities of AgNPs were assessing. When the concentration of AgNPs increased to 62.5 μg/mL, the free radical scavenging rate was 70% meaning a good antioxidant activity. Furthermore, the AgNPs generated by Cornus officinalis aqueous extract revealed significant inhibition on the growth of S. aureus and E. coli, where the MIC values were 3.9 and 7.8 μg/mL, respectively. The IC50 values for colorectal cancer cell HCT116 and SW620 were 23.1 and 35.1 μg/mL, respectively, indicating a good anticancer activity.