<p>The efficient and accurate Legendre Galerkin spectral element method is proposed for the generalized Rosenau-type equations. Our primary contribution lies in the innovative integration of the diagonalization technique with Sobolev bi-orthogonal basis functions, which significantly reduces the number of non-zero matrix elements and enhances computational efficiency. This method holds certain significance in addressing the computational challenges of these equations, optimizing the solution process while maintaining numerical stability. Additionally, we analyze the conservation properties of the semi-discrete scheme. Numerical results confirm the effectiveness of our approach and demonstrate its potential in solving generalized Rosenau-type equations.</p>