An optimization design scheme is proposed for the femtosecond laser induced corona discharge experiment. The differences between spherical electrode and traditional cone electrode are investigated by numerical analysis. The distribution of space electric field around femtosecond filament is demonstrated, and the thresholds of corona electric field around femtosecond laser filament tip under the two situations are compared. The experimental phenomena of corona discharge of the two electrodes induced by femtosecond laser are compared. The simulation and experiment results show that the new designed spherical electrode dramatically improves the coupling efficiency between the femtosecond laser filament and the external electric field and the efficiency of corona discharge induced by femtosecond laser.