A dual-mode metasurface device is designed to achieve phase modulation with anisotropic response depending on the left and right-handed circularly polarized light. This device can control the sizes of the Si nanoblock in order to regulate the transmission phase, and require additional geometric phase by controlling its in-plane direction, simultaneously. By combining the two phases, the metasurface focuses the right-handed circularly polarized incident beam with an efficiency as high as 44.8%, while keeping the plane wavefront transmission of the left-handed circularly polarized incident beam. The designed metasurface could be used as a miniaturized polarizer in information encrypted transmission field.