The Hawking radiation of charged Dirac particles on event horizon of Kerr-Newman black holes is studied in this paper. First, we construct the symmetrized null tetrad from which the symmetrized spin coefficients and Dirac equation are derived. Next, we solve the Dirac equation near the event horizon and get the four component ingoing and outgoing wave functions. Finally, by analytic continuation, the Hawking thermal spectrum formula of Dirac particles for arbitrary Kerr-Newman black holes is obtained.