Trademarks are common graphic signs in human society. People used this kind of graphic sign to distinguish the signs of representative significance such as individuals, organizations, countries, and groups. Under effective use, these graphic signs can bring maintenance and development resources and profits to the owner. In addition to maintenance and development, organizations that have obtained resources can further promote national and social progress. However, the benefits of these resources have also attracted the attention of unfair competitors. By imitating counterfeit trademarks that appear, unfair competitors can steal the resources of the original trademark. In order to prevent such acts of unfair competitors, the state has formulated laws to protect trademarks. In the past, there have also been researches on similar trademark searches to assist in trademark protection. Although the original trademark is protected by national laws, unfair competitors have recently used psychological methods to counterfeit the original trademark and steal its resources. Trademarks counterfeited through psychology have the characteristics of confuse consumers and do not constitute infringement under the law. Under the influence of such counterfeit trademarks, the original trademark is still not well protected. In order to effectively prevent such trademark counterfeiting through psychology, this article proposes new features based on trademark design and Gestalt psychology to assist legal judgments. These features correspond to a part of the process that is not fully understood in the human visual system and quantify them. In the experimental results, we used past cases to analyze the proposed assistance system. Discussions based on past judgments proved that the quantitative results of the proposed system are similar to the plaintiff or the judgment to determine the reasons for plagiarism. This result shows that the assistance system proposed in this article can provide visually effective quantitative data, assist the law to prevent malicious plagiarism on images by unfair competitors, and reduce the plagiarism caused by the similar design concepts of late trademark designers.