Dog-bite injuries pose significant threat to children globally. School-age children are especially at risk because of their insufficient safety knowledge and cognitively immature tendency toward low perceived vulnerability to bites, and this risk is elevated further for school-age children living in rural China due to the large number of stray dogs, all potential rabies carriers, present in their communities. Method: This randomized controlled trial evaluated whether viewing an educational video of testimonials would change safety knowledge, perceived vulnerability, and simulated behaviors with dogs among a sample of 280 third and fourth graders living in rural China. Participants were randomly assigned to view either an educational video of testimonials on dog-bite prevention (treatment) or an educational video of testimonials on drowning prevention (comparison). Safety knowledge, perceived vulnerability to dog bites, and simulated behavior with dogs using a dollhouse model were assessed both before and after exposure to the video of testimonials. Results: Children who watched the educational video of testimonials on dog-bite prevention had increased safety knowledge, higher perceived vulnerability, and less risky simulated behaviors with dogs compared with the comparison group. Mediation analysis revealed that the intervention successfully changed children's simulated behaviors with dogs through greater safety knowledge and increased perceived vulnerability. Conclusions: Results suggest the incorporation of testimonials into injury prevention programs has potential for broad global dissemination. The fact that both increased knowledge and heightened perceived vulnerability mediated changes in simulated behavior suggests the dual roles of knowledge and appraisal on children's injury-risk behavior.