In this paper, one curved active phase gradient metasurface (PGM) is proposed for enhancement of RCS of a special obtuse dihedral corner, while the other is planar PGM. the active metasurface structure loaded on a special obtuse dihedral corner is proposed. By loading the metasurface cells with varactor diodes, the reflection phase can be dynamically tuned in the presence of an external adjustable voltage source.As a result, the simulations show that the proposed structure enhances the RCS of 10GHz band significantly in the wide angle, and in the low scattering region, the RCS enhancement can reach more than 20dB.