According to the nature of international law, sanctions implemented by a state or collective of states can be divided into "multilateral sanctions" authorized by the United Nations and "unilateral sanctions". Unlike multilateral sanctions, unilateral sanctions cannot obtain legitimacy from Security Council resolutions, and their legality is subject to significant controversy. International law does not generally prohibit unilateral sanctions, but this does not mean that every unilateral sanctions measure complies with existing principles of international law and international treaties.Unilateral sanctions may potentially violate specific treaty obligations under the WTO system, as well as the principle of non-interference in the domestic affairs of other countries. However, the illegality of such sanctions can be excluded when these actions meet the requirements of exception clauses or comply with the substantive and procedural requirements for "countermeasures". In reality, the specific content of sanctions varies, making it impossible to directly determine the legality or illegality of unilateral sanctions. Instead, a systematic analysis should be conducted in conjunction with specific circumstances.