The invention discloses a method for shifting hung risers of a deepwater drilling platform. The method includes the steps that an inner-layer casing pipe is severed and thrown away, an abandonment cement plug is injected, then diverters are thrown, flexible joints are thrown through a riser running tool, expansion joint inner cylinders are locked, BOPs are unlocked, supporting rings are unlocked,tensioners are moved, and BOP set control pipeline supporting frames and goosenecks are dismantled; an auxiliary tugboat advances to a target well site and records water area and weather related dataon the way; then, the risers and BOP sets are backed off from a wellhead connector, the risers are pulled/thrown to be fed, expansion joints are pulled/thrown, and 7-8 risers are pulled, so that the platform is in a floating state; a main tugboat tugging the drilling platform advances to the target well site; after the main tugboat arrives, another derrick is used for drilling a surface layer anda wellhole, a high-pressure wellhead housing is put in, the boat is moved to make the hung risers and BOP sets seated on the high-pressure wellhead housing, and after connection is completed, next operation is performed. The method is convenient to implement, improves the shifting efficiency and is beneficial to reducing the drilling production cost.