Abstract: Finite element method of lines (FEMOL) is an excellent semi-discrete method. To improve the accuracy along the discrete direction, the Element Energy Projection (EEP) method, which is a powerful super-convergent recovery method in 1D FEM, was successfully extended to FEMOL. Accordingly, a set of formulas named simplified formulation was proposed in previous papers. The displacement and its derivatives calculated by the simplified formulas have been proved to have one order higher convergence than that of FEMOL itself. However, deepened studies showed that the formula for derivatives in this simplified formulation could be further simplified and a more simplified formula for derivatives is proposed in this paper. Numerical experiments are conducted to demonstrate the effectiveness of the proposed approach.