Digital coding and digital modulation are the foundation of modem information science.The combination of digital technology with metamaterials provides a powerful scheme for spatial and temporal controls of electromagnetic waves.Such a technique,however,has thus far been limited to the control of free-space light.Its application to plasmonics to shape subwavelength fields still remains elusive.Here,we report the design and experimental realization of a tunable conformal plasmonic metasurface,which is capable of digitally coding and modulating designer surface plasmons at the deep-subwavelength scale.Based on dynamical switching between two discrete dispersion states in a controlled manner,we achieve digital modulations of both amplitude and phase of surface waves with nearly 100％ modulation depth on a single device.Our study not only introduces a new approach for active dispersion engineering,but also constitutes an important step towards the realization of subwavelength integrated plasmonic circuits.