A similarity measurement method includes: obtaining a directional relationship between nodes in a network, and determining a transition matrix; calculating a constraint matrix according to the transition matrix and an obtained attenuation factor; constructing a system of linear equations, where a coefficient matrix of the system of linear equations is the constraint matrix, and a variable of the system of linear equations is a correction vector; solving the system of linear equations by means of iteration by using a Jacobi method, and determining the correction vector; and calculating similarities between the nodes according to the transition matrix, the attenuation factor, and a diagonal correction matrix that is generated according to the correction vector. In the method, the correction vector is determined by using the Jacobi method, and further the similarities between the nodes may be calculated.