If there are n risk factors for the disease, we want to know whether the n risk factors interact with each other, which is very important in biomedical statistics.However, this paper only discusses two risk factors, constructing the risk factors on the Cox regression model and using the Bernstein polynomial to describe its baseline cumulative risk function. For the research-type II interval-limited survival data, Bayesian statistics are used to analyze whether or not two risk factors interact. In the parameter Bayesian estimation, the Markov chain Monte Carlo is used for calculation purposes, and their performance is considered quite practical since their simulation results have the property of large samples.