In order to overcome the shortcomings of the existing models that use only the node degree distruibution to construct the worm network,a worm propagation model with both random and preferential attachments is proposed,which considers both the property of scale-free network and the characteristics of real P2P network communication,and introduces a adjustment parameter representing the new node connection probability.Then,the evolution mechanism of the model is investigated based on the mean-field theory through Matlab simulation.Theoretical and simulated results show that the connection between the suitable nodes selected from the worm network and the newly-infected host is tightly related to the connection probability and the node attraction,and that the established worm network is scale-free.