Legendre wavelet based numerical method has been developed for the solution of the system of non-linear differential equations arising in the study of a Marangoni convective flow of dusty Ree-Erying fluid over a Riga plate in Darcy-Forchheimer medium with Soret, Dufour, non-linear radiation, activation energy effects and entropy generation analysis. The proposed method is validated by comparing the solutions of the test problem with the Bernoulli wavelet based numerical method and the exact solution and by comparing the results of the considered dusty fluid problem for some fixed parameters with the previously published results. The effects of various factors on the velocity, thermal, concentration attributes are studied by using the proposed method. It is observed that the Ree-Erying fluid parameter and Marangoni ratio parameter escalates the velocity and declines the temperature and concentration. The opposite behaviour is observed for Deborah number. The concentration declines for higher chemical reaction parameter and improves for activation energy. Both entropy generation and Bejan number escalates for radiation parameter and diffusion parameter. The proposed method is reliable, fast computable and powerful tool to solve the differential equations.