The work aims to construct the post-emotional evaluation scale and standard of WeChat H5 advertising, and verify the hypothesis of post-emotional art expression form in WeChat H5 advertising through investigative analysis. Firstly, WeChat H5 advertising was defined as the research object, and the research equipment was evaluated and measured. Secondly, the advertising sample was extracted according to the sampling method, and the type analysis was performed. Finally, quantitative research method was adopted to carry out the post-emotional scale survey and evaluation and verify the hypothesis by data analysis. Four types of WeChat H5 advertising of games, tests, generations, and videos had post-emotional design forms and characteristics. The research results verified the hypothesis of post-emotional expression form in WeChat H5 advertising, which also confirmed the existence of this new post-emotional expression form in new media advertising. The method constructs the post-emotional evaluation scale and standard, which provides a reference method for post-emotional design of WeChat H5 advertising, and establishes a new perspective of the correlation between new media advertising design and post-emotion.