In　this　paper,　the　mesocalibration　test　was　used　to　measure　the　contact　parameters　(restitution　coefficient,　rolling　friction　coefficient,　static　friction　coefficient,　and　surface　energy)　between　coarse　aggregate　particles　and　mortar　particles　in　Discrete　Element　Method　(DEM)　model　of　concrete.　Then,　the　DEM　model　of　concrete　slump　was　established　according　to　the　coarse　aggregate　gradation　to　study　the　flow　behavior　of　coarse　aggregate　in　fresh　concrete.　The　slump　test　result　was　compared　with　the　output　of　the　slump　DEM　model　with　high　consistent,　indicating　the　promising　reliability　of　the　mesocalibration　test.　Finally,　based　on　the　mesocalibration　test　results,　the　DEM　model　of　pumping　concrete　was　established.　It　was　obtained　that　the　pumping　pressure　calculated　by　the　numerical　model　was　similar　to　that　of　the　pumping　test　with　satisfactory　accuracy　better　than　the　concrete　pumping　pressure　calculated　according　to　the　rheological　test　results　of　concrete　and　lubricating　layer.　On　this　basis,　the　movement　trajectory　of　coarse　aggregate　in　the　pump　pipe　was　analyzed　and　the　influence　of　coarse　aggregate　on　the　pumping　performance　of　concrete　was　revealed.