Euthanasia is a key welfare issue and focus of ethical reviews in laboratory animal experiments. With increased awareness of the importance of animal protection and the promulgation and implementation of national standards of welfare ethics for laboratory animals, the issue of euthanasia has attracted increasing attention. Based on the current situation of the international application of euthanasia, this paper expounds the main problems associated with the implementation of euthanasia on laboratory animals, compares the advantages and disadvantages of several euthanasia method commonly used globally, presents an ethical analysis, and proposes some suggestions.