Abstract: In order to optimize the double-wave synergistic drive efficiency between electron cyclotron wave (ECW) and lower hybrid wave (LHW) on EAST, and obtain a larger synergy current to maintain a long pulse operation, some numerical simulations of synergistic effect with different EAST plasma parameters were carried out by using C3PO/LUKE code based on the physical mechanism of synergy. The synergy current and synergy factor were given. The calculation results show that the synergistic effect is the best when the positions of current density peak of the LHW and ECW overlap. And the increase of electron density and electron temperature can lead to the change of overlap region of two waves, and then affects synergistic effect.