The main contents of consistency theory is discussed systematically; the coherent viscoplastic tangent modulus is deduced; also the generalization condition and method for analogy Hoffman material is researched base on some result of Winnicki and Xiao-shiyun; and linear Drucker-Prager model is generalized to consistency model; backward Euler algorithm of FEM for generalized model is presented; the results of numerical example is compared with experiment data to show the validity of consistency Drucker-Prager model finally.