This thesis presents the design and analysis of a photonic crystal fiber (PCF)-based surface plasmon resonance (SPR) sensor utilizing quadruple microchannels, with gold as the plasmonic material for stability. Numerical investigations are conducted using COMSOL Multiphysics software. The sensor demonstrates high wavelength sensitivity (WS), amplitude sensitivity (AS) , and a figure of merit in the refractive index (RI) range of 1.29-1.41. By modifying the design with air holes and repositioning the gold layer, the sensor's performance varies, making it suitable for detecting various chemical, biochemical, and organic molecular analytes.