We consider a type of singular perturbation convection diffusion problems, construct a difference scheme for the problem on a Vulanović-Bakhvalov mesh, and apply differential evolution algorithm to optimize two parameters of the Vulanović-Bakhvalov mesh to obtain the optimal numerical solution. We do numerical simulations for two examples, and the numerical results show that the numerical solution obtained on Vulanović-Bakhvalov mesh by differential evolution algorithm is significantly superior than the numerical results obtained by fixing the mesh parameters. The numerical results are convergent with low computational complexity.