Metasurfaces have been widely investigated for various applications enabled by their strong light manipulation capabilities. Their monolithic designs offer the convenience to incorporate novel natural materials in order to realize advanced electromagnetic (EM) functionalities. Here, based on the usage of the phase change material vanadium dioxide (VO2), a switchable metasurface that could work at two different working states is proposed. With insulating VO2, we show that helicity-dependent metasurface could be rigorously designed by adopting two phase variables, i.e., initial phase and Pancharatnam-Berry (P-B) phase, which is verified by showing an asymmetric photonic spin Hall effect (APSHE). When VO2 goes into the metallic phase (e.g., by raising the operating temperature above ~341K), the loss factor of the unit cell will be enhanced, and in this case with the assistance of multi-mode resonances, the metasurface will turn into a perfect broadband circular-polarization-insensitive EM absorber. Based on these, switchable beam splitters and focus-lenses have been designed and discussed in the paper. The method proposed here may pave a new way to pursue active and multifunctional optical devices.