In the post-epidemic era, it is difficult for farmers to sell agricultural products offline due to their characteristics, and farmers once again fall into the situation of “difficult sales.” New media marketing of agricultural products, as an emerging form conforming to the trend of the times, not only increases farmers’ income but also promotes industrial integration and development. However, as this model is still in the early stage of development, a large number of farmers are not willing to transform the traditional sales channels into new media marketing for agricultural product sales. In this study, the interview data of 76 new-type professional farmers in Fujian were analyzed by three-level coding based on programmed grounded theory. It is found that core factors, and macro- and microfactors such as farmers’ characteristics and sales situation will affect farmers’ willingness to sell agricultural products through new media. Therefore, this study deeply explores the relationship between farmers’ willingness and various factors and puts forward three suggestions for solving the actual problems of agricultural product sales.