Independent manipulation of Circularly-Polarized(CP) terahertz waves is an important topic in the terahertz technology field, and metasurfaces provide a convenient solution for it. A new scheme is proposed for amplitude and wavefront control of Circularly-Polarized terahertz waves based on a chiral metasurface. By hybridizing chiral phase and Pancharatnam-Berry (P-B) phase, spin-decoupled functionality is realized, while the reflection efficiencies of the two wave components are both greater than 70%. Further exploiting of the broken rotational symmetry of the metasurface unit cells changes the amplitude response of the reflected terahertz waves, thereby enabling simultaneous manipulation of wavefront and amplitude. A metasurface reflector and a selective absorber are respectively designed for functional verification, proving the effectiveness of the proposed scheme. The scheme offers a new technical route and possibilities for multi-dimensional quasi-optical control of terahertz waves.