Abstract: To explore the phenomenon of infected individuals with different infectious rates,based on the basic SIR epidemic model in complex networks,this paper proposed an epidemic model with two types of infections and probability of metastasis.Based on the existence of the equilibrium point of endemic diseases,it obtaines the basic reproduction number R₀.It analyzes two common immunization strategies:random immunization and target immunization.Simulation experiments show that under the same conditions,diseases spread faster and wider in heterogeneous networks than in homogeneous networks when R₀>1,and network structure has little influence on the spread of diseases when R₀<1.Further researches show that the greater the degree of initial infection nodes in the network,the faster the disease transmission speed and the greater the peak value;the greater the centrality of the proximity of the initial infected nodes,the faster and wider the disease spreads;the point aggregation coefficient has little effect on the transmission process;the basic reproduction number decreases with the increase of the transfer probability,and the increase of the transfer probability can effectively reduce the spread of disease;in the case of the same average immunity rate,the target immunity is more effective than random immunity.

Key words: Basic reproduction number, Complex network, Heterogeneous infectivity, Immunization strategy, State transition