The Dungannon rider suffered chest and pelvic injuries in the crash on 12 May.
His condition was described as stable on 16 May and he was moved out of intensive care.
The 40-year-old and Dan Cooper came off their bikes on the the Black Hill section of the course.
English rider Malachi Mitchell-Thomas was killed in a crash at the same part of the course on Saturday, 14 May.
Cooper was taken to the Causeway Hospital in Coleraine with shoulder injuries but was later discharged.
Farquhar is a well known-figure in motorcycling and has won five races at the North West 200.
He retired from the sport in 2012 following the death of his uncle Trevor Ferguson at that year's Manx Grand Prix in the Isle of Man.
However, Farquhar resumed his road racing career in 2014, saying that his family backed his decision to return.
Motorcycle racer Ryan Farquhar, who was hurt in a high-speed crash in the North West 200, is seriously ill and has returned to intensive care, the Belfast Trust have said.