In order to flexibly adjust the deflection direction of terahertz wave,a three -layer PB phase-encoded metasurface composed of multiple nanorods and circular metal notc hes is proposed in this paper,which has a perfect geometric phase modulation effect on the tran smitted wave at 0.737THz and improves the efficiency and bandwidth of scattered light to a good extent,thereby expanding the application field of nanorods.The manipulation of continuous tran smission angle requires the continuous change of encoding metasurface period.Since the size of encoding particles in the coded metasurfaces cannot be designed to be infinitesimally sma ll,it is impossible to obtain the continuously changing period of coded metasurfaces.In order to ob tain the continuous manipulation of transmission scattering angles,we introduce the Four ier convolution theory in digital signal processing to realize the addition or subtraction of th e encoded metasurface, so as to achieve the arbitrary control of the transmission scattering angle.The refore,it can be extended to control all directions of light waves by performing multiple Fourier convolution operations on different code sequences,which provides a greater experimental ba sis for the free and flexible operation of visible light,and it can also be analogously applied to microwave and terahertz frequency bands,opening up new paths for real-time control of electr omagnetic waves and beam scanning.