Police were alerted to the grisly discovery on the A720 near the Sheriffhall roundabout after drivers raised the alarm at around 8.20am on Thursday.
The road between the Gilmerton and Sheriffhall Junctions has been completely closed to all traffic in both directions for more than six hours and will remain closed during the evening peak.
In a tweet, Traffic Scotland said: “Be aware A720 will remain closed both ways between Gilmerton and Sheriffhall throughout this evening’s peak. Please plan your journey ahead. Congestion E/B is back to Lasswade and W/B to Millerhill already.”
The man’s death is being treated as unexplained and a report will be sent to the Procurator Fiscal.
Detectives are still at the scene, along with forensics and road policing officers.
A Police Scotland spokeswoman said: “Police in Midlothian are currently in attendance on the A720 near to the Sheriffhall Roundabout following the discovery of a man’s body on the central reservation
“The incident was reported to police around 8.20am on Thursday, January 17.
“Inquiries into the full circumstances are ongoing, and the death is being treated as unexplained. A report will be sent to the Procurator Fiscal.
“Closures are currently in place on the Edinburgh City Bypass in both directions. The public is thanked for their patience at this time.”
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