Driven by the sharing economy boom, with the increasingly mature mobile terminal market, the combination of mobile communication and the internet has given birth to many new knowledge payment platforms. Knowledge payment platform has formed a new knowledge transaction method with its unique way of knowledge production and huge knowledge demand of users. The knowledge payment platform is the core of knowledge payment, but it is still in the initial stage of development. As an early explorer in the industry, "Zaihang yidian" has been exploring a new mode of voice payment, which is representative in the field of knowledge payment. Therefore, based on the concept of "paying for knowledge ", this paper firstly explores the development process and categories of the paid Q&A platform. Secondly, based on the 4P theory, this paper analyzes the content marketing strategy of the "Zaihang yidian" paid voice Q & A platform. Thirdly, conducts an in-depth analysis of the difficulties faced by the pay Q & A platform of " Zaihang yidian", such as ephemeral star effect,the classification method is not reasonable, 60 seconds paid Q & A has become a short board for development, fragmented knowledge is difficult to precipitate, voice content supervision is absent, etc. Finally, this paper tries to put forward some corresponding countermeasures and suggestions from the aspects of establishing screening mechanism, establishing evaluation mechanism, strengthening supervision mechanism and improving service mechanism.