This　research　presents　a　simulation　of　hydraulic　fracturing　process　in　a　naturally　fractured　reservoir　based　on　a　discrete　fracture　network　(DFN)　model　coupling　different　kinds　of　pre-existing　discontinuities.　Natural　fractures　and　bedding　planes　obtained　from　outcrops　and　downhole　camera　in　the　Ordos　Basin　of　China　are　used　to　build　a　three-dimensional　DFN　model.　The　propagation　of　hydraulic　fractures　in　the　layered　and　naturally-fractured　reservoir,　and　the　complex　interactions　between　hydraulic　fractures,　natural　fractures　and　bedding　planes　are　simulated　using　the　displacement　discontinuity　method.　The　results　show　that　strong　interactions　between　hydraulic　fractures　and　pre-existing　discontinuities　occur　during　fluid　injection,　causing　complex　fracture　geometry.　When　the　injection　rate　is　0.01　m3/min,　only　one　major　hydraulic　fracture　is　induced,　and　crack　growth　along　bedding　interface　does　not　occur　since　the　fluid　pressure　is　not　high　enough.　With　increasing　injection　rate　(0.1　m3/min　and　1.0　m3/min),　natural　fracture　and　bedding　planes　are　activated,　inducing　multiple　major　hydraulic　fractures　and　reticulated　fractures.　For　each　injection　scheme,　fracture　geometry　in　the　horizontal　and　vertical　directions　becomes　more　complex　with　the　injection　of　fracturing　fluid.　However,　fracture　complexity　in　the　horizontal　direction　is　smaller　than　that　in　the　vertical　direction　when　the　injection　rate　varies　from　0.01　m3/　min　to　1.0　m3/min.　Besides,　the　results　show　that　injection　rate　has　a　strong　positive　influence　on　the　increment　of　fracture　complexity.