Wax　plug　growth　in　pipeline　pigging　significantly　impacts　the　crude　oil　transportation,　even　resulting　in　a　wax　blockage　accident　of　pipeline.　A　pigging　facility　was　constructed　to　conduct　the　pigging　experiments.　A　physical　model　was　proposed　to　illustrate　the　mechanism　of　wax　plug　transportation.　Furthermore,　a　theoretical　model　was　developed　to　estimate　the　wax　plug　transportation　force　per　unit　contact　area.　It　is　found　that　the　wax　plug　transportation　force　per　unit　contact　area　is　independent　of　the　wax　plug　length　and　radius,　while　correlated　to　the　wax　yield　stress　and　the　interfacial　lubrication　coefficient.　These　predicted　correlativities　match　with　the　experimental　results.　Additionally,　the　experimental　results　show　that　the　wax　plug　transportation　force　per　unit　contact　area　is　independent　of　the　pig　geometry　and　hardness.　With　the　experimental　results,　the　interfacial　lubrication　coefficient　for　wax　sample　prepared　from　crude　oil　and　diesel　oil　were　calculated　to　be　0.0749　and　0.0442,　respectively.　It　is　indicated　that　the　extruded　diesel　oil　at　the　contact　surface　provides　a　better　lubrication　effect　for　wax　plug　transportation　than　the　extruded　crude　oil.　Experiments　with　different　pig　geometries　and　hardnesses　were　performed　to　verify　the　modeling　results.　The　cases　of　two　field　wax　blockage　accidents　were　used　for　validation.　With　the　results　from　the　developed　model,　an　engineering　implication　was　presented　accounting　for　formation　condition　of　wax　blockage　and　emergency　operation　scheduling　as　well　as　selection　of　an　appropriate　pig　diameter.