In this paper，the problem of vertical infection of babies with cytomegalovirus in breast milk isconsidered，a dynamic model of cytomegalovirus is established，the equilibrium stability condition of the model is given，and the effect of randomness of breast milk feeding on the threshold value is analyzed. According to the classification criteria of cytomegalovirus infection define by the“Expert Consensus 2017”，the limiting conditions of the probability of breast-feeding are given. The different probability of breast milk treatment for cytomegalovirus infection in infants is numerical simulated and recommendations for safe feeding are made