In the large data environment, the traditional digital information publishing system often does not consider the risk of information publishing, and its corresponding efficiency and risk resistance capacity become poor. Therefore, this paper designed a new digital information publishing system based on cloud computing and risk assessment model. Firstly, we designed the overall structure of system. This system consists of data layer, support layer and application layer. Then, we analyzed the work flow of system in details; secondly, this paper proposed the risk assessment algorithm based on the theory of risk perception. Combined with cloud computing environment, we calculated cloud matching degree of data. Combined with the matching degree, we designed the evaluation model to realize the effective evaluation of security risk in information dissemination system. Thus, we built the digital information publishing system, realizing the digital information publishing under low risk. Experiments show that the designed information publishing system could solve the disadvantages of the traditional method, which has high response efficiency and strong ability to resist risks.