Over the past decade, in-feed native advertising has become one of the most popular forms of online advertising, attracting attention from both academia and industry. Compared to traditional online ads, in-feed native ads are less intrusive and have more engaging content, effectively reducing users' tendency to avoid ads and improving advertising effectiveness. Despite existing review studies, most of them focus on specific aspects of in-feed native advertising, such as ad identification, disclosure, or regulation, and lack an overview of the relevant literature. Moreover, with the diversified development of digital media forms, the widespread application of AI technologies, and the improvement of consumers' ad literacy, in-feed native ad research faces new issues and practical challenges. Thus, a systematic review of existing research is necessary to identify valuable future research directions.