An integrated dual-channel sensing method utilizing polarized dissimilation is investigated with an appropriately designed plasmonic metasurface. By assembling two different kinds of nano-gold antennas to constitute a periodic array, the phase of diffraction fields contains both spin-dependent geometric phase and resonance-dependent dynamic phase components. Accurate control over the superposition of orthogonal spin components utilizing strong photonic spin-orbit interaction of metasurface leads to dissimilar response of different diffraction orders. The simulation shows that the linear polarization of ±1 diffraction orders rotate in the reverse direction (±19°) with the refractive index variation (1.3-1.5). The sensing method exhibits an extremely high signal-to-noise ratio and stability.