The　3-D　base　force　element　method　(BFEM)　for　damage　problems　is　proposed,　which　is　applied　to　analyze　the　damage　mechanism　of　recycled　aggregate　concrete　(RAC).　A　piecewise　curve　damage　constitutive　model　is　given　to　simulate　the　constitutive　relationships　of　RAC　phases.　A　spatial　random　aggregate　model　of　RAC　is　proposed.　3-D　numerical　simulations　of　RAC　under　uniaxial　mechanical　stress　are　carried　out.　The　macroscopic　stress-strain　relationship　and　failure　process　of　RAC　under　uniaxial　stress　based　on　the　3-D　BFEM　are　obtained.　The　numerical　results　show　a　good　consistency　with　the　experimental　results.　This　illustrates　that　the　numerical　simulation　can　reflect　the　nonlinearity　deformation,　stress　redistribution,　and　crack　propagation　process　of　RAC.　In　addition,　the　influence　of　recycled　aggregate　replacement　percentage　on　strength　and　elastic　modulus　is　investigated.　The　results　show　that　the　content　proportion　of　recycled　aggregate　has　a　great　effect　on　RAC,　which　have　to　be　considered　in　the　analysis　and　the　application　of　RAC.