Extraordinary optical transmission (EOT) in subwavelength metal structures has been studied widely. Herein, we propose a strategy for tuning the EOT of the bullseye structure. Specifically, the bullseye structure was immersed in a nonlinear medium, and a controlling light was employed to change the refractive index of the medium. At different intensities and distributions of controlling light, the transmission property of signal light in the bullseye structure was simulated. The results show that a variable transmission spectrum in the bullseye structure can be realized. Moreover, the position of the central transmission peak shifts linearly with the increasing intensity of controlling light.