The all-optical wavelength conversion technology based on four-wave mixing is important for all-optical signal processing. Wavelength conversion is the process of converting blocked data to other idle wavelengths for output through a wavelength converter, which can solve the problems of insufficient resource allocation and reduced communication quality. Both silicon-based waveguides and photonic crystal fibers can be used for wavelength conversion; however, for short distance communication, silicon-based waveguides are more advantageous. In this study, a novel MEH-PPV (1-methoxy-4-(2-ethylhexyloxy)-p-phenylenevinylene) silicon-based optical waveguide is constructed, and its dispersion is controlled using the finite element method. The phase mismatch characteristics and nonlinear coefficients of the waveguide under an optimal structure are analyzed. A four-wave mixing mathematical model based on pump degeneracy is established by combining the transmission loss, phase mismatch characteristics, and nonlinear coefficients of the waveguide. The wavelength conversion effects under different signal and pump powers and waveguide lengths are also analyzed. The maximum wavelength conversion efficiency of the slot silicon-based waveguide with the MEH-PPV material as a sandwich is approximately 16 dB, and its conversion bandwidth is approximately 400 nm, revealing its wide scope of application in the field of all-optical signal processing.