The purpose of this paper is to discuss the Financial Fraud of Merger and Acquisition (M&A) Target of public company in the process of M&A of target company, and take the case of Grand Image Advertising being merged and acquired by Tianshan Animal Bio-engineering as an example for in-depth analysis. Firstly, starting from the background and significance of M&A activities of public companies, it is pointed out that weak regulation leads to the prominence of financial fraud problems, especially in the context of the full implementation of the registration system for the issuance of shares, the market is facing new opportunities and challenges. This paper analyses the motivation of Financial Fraud of Merger of M&A Target of public company through GONE theory. At the same time, combined with cases, it analyses the signs of financial fraud in depth. Finally, this paper puts forward suggestions on how to prevent Financial Fraud of M&A Target of public Company. This study provides useful theoretical and practical references for further promoting the reform of comprehensive registration system, standardising the market regulatory environment, and guiding the market participating institutions to practice correctly.