Based on the DL conjugate gradient method with secant equation,two modified DL conjugate gradient methods with the modified secant equation are proposed,which are called MDDL1 method and WMDDL1 method.The MDDL1 method can be proved to satisfy the sufficient descent condition when step size is obtained by Wolfe line search.Furthermore,the WMDDL1 method satisfies sufficient descent condition independent of any line search.Alternatively,the two methods can be proved to possess global convergence for general functions when step size is obtained by strong Wolfe line search.