The　three-dimensional　discontinuous　deformation　analysis　(3D-DDA)　method　was　developed　for　the　deformation　simulation　of　rock　block　system　cut　by　the　natural　discontinuities　in　rock　mass　engineering.　In　the　conventional　DDA,　open-close　iteration　is　used　to　deal　with　the　contact　constraints,　which　needs　to　apply　or　remove　the　normal　or　tangential　springs　repeatedly　to　meet　the　equilibrium　equations　at　each　time　step.　DDA　provides　a　time　step　adjustment　strategy　to　meet　the　fast　convergence　of　open-close　iterations,　but　when　solving　large-scale　problems,　the　adjusted　time　step　often　reaches　a　very　small　order　of　magnitude,　which　makes　the　calculation　time-consuming　increase　sharply.　In　the　framework　of　the　original　3D-DDA,　a　new　contact　potential　based　three-dimensional　discontinuous　deformation　analysis　method　(3D-CPDDA)　is　developed.　The　proposed　method　not　only　retains　the　advantage　of　the　original　DDA　method　in　defining　local　displacement　functions　on　a　single　patch,　but　also　integrates　the　simplicity　and　rapidity　of　potential　based　contact　processing.　The　improved　method　is　easier　to　be　implemented　in　the　parallel　way,　which　can　further　improve　the　computational　efficiency.　Numerical　examples　have　confirmed　the　correctness　and　feasibility　of　the　proposed　procedure.