Stray cats and dogs are now a significant problem in many urban areas around the world. Although stray animals seem unimpressive, they have caused negative impacts such as parasites and infectious diseases related to animal contact, hydrophobia due to animal attacks, traffic accidents, and other impacts on mental health and the environment. There exist plenty of traditional approaches around the world to deal with stray animal problems, but each of them has its shortage. This paper discusses the impact of stray animals and implements a cost-benefit analysis of the trap-neuter-return approach to deal with the stray animal problem. The costs include the expenditures on different procedures of this approach, and the benefits include the loss deduction for human health and the environment. The paper offers a detailed approach to evaluate the cost and benefits, although the actual surveys and calculations are not implemented due to the covid-19 epidemic restrictions. This paper also provides some policy suggestions on how to solve stray animal problems: a diverse and multi-party approach is needed to solve this problem effectively. The essay could be used as a reference for the government to study how to deal with the stray animal problem.