A　three-dimensional　thermal-hydro-chemical　(T-H-C)　coupled　unified　pipe-network　method　(UPM)　is　developed　to　simulate　the　process　of　acidizing　treatment　in　fractured　carbonate　rock.　The　concept　of　the　traditional　two-scale　continuum　model　is　extended　by　considering　thermal　effects　and　incorporating　multiphysical　governing　equations　for　explicitly　represented　fractures　in　the　current　method.　An　effective　conforming　mesh　method　is　employed　in　the　element　discretizing　procedure　for　the　complex　fracture　network　system.　Both　rock　matrix　and　fractures　are　modeled　by　three-dimensional　equivalent　pipe　networks　to　simulate　the　H-T-C　coupling　process　in　fractured　carbonate　rock.　The　fluid　transfer　between　rock　matrix　and　fractures　is　solved　by　a　superposition　principle,　without　introducing　the　interchange　terms.　This　straightforward　method　simplifies　the　programming　process　in　simulating　rock　dissolution　by　acid.　The　accuracy　of　the　thermal-hydro　coupled　process　is　verified　against　commercial　software　(COMSOL　Multiphysics)　result.　The　reliability　of　modelling　the　acidizing　process　at　different　temperatures　is　demonstrated　through　comparison　with　previous　experimental　results.　Numerical　experiments　indicate　that　the　presence　of　a　fracture　network,　varying　reservoir　or　inlet　acid　temperature,　and　formation　heterogeneity　all　influence　the　acidizing　efficiency.　The　fracture　network　reduces　the　volume　of　acid　being　injected　but　has　no　influence　on　the　dissolution　pattern　corresponding　with　specific　injection　rates.　The　optimal　injection　rate　increases　to　from　a　dominant　wormhole　in　the　case　with　high　formation　temperature.　The　acidizing　efficiency　is　reduced　when　acid　with　a　high　temperature　is　injected.　And　both　optimal　injection　rate　and　injection　volume　increase.　For　the　influence　of　formation　heterogeneity　on　the　dissolving　patterns,　conical　dissolution　is　observed　in　comparatively　more　homogeneous　formations　with　lower　porosity　heterogeneity.　However,　ramified　dissolution　occurs　in　the　extremely　heterogeneous　formation,　and　the　existence　of　fracture　networks　have　less　influence　on　the　development　of　wormhole　branches.　These　aforementioned　factors　should　be　considered　in　practical　field　design　to　approach　optimal　acidizing　results.