The road was closed as an air ambulance was sent to the scene near Limekiln Bank Roundabout at around 7.45am on Monday.
A blue VW Polo and an orange Ford Ranger were involved in the crash, with both vehicles spinning across the road before stopping.
The female driver of the Polo, aged in her 30s, suffered "significant internal injuries" and was taken for treatment at Royal Stoke University Hospital, which has a major trauma centre.
The man who was driving the Ford was not seriously hurt and was discharged at the scene.
There was heavy congestion on surrounding roads as the woman was treated and the scene was cleared, with the road closed between Redhill Way and the A5 at Crackley Bank as a result.
West Mercia Police is investigating and has now urged any witnesses or people with dash-cam footage to come forward.
The Polo was heading towards Telford and the Ranger was heading towards Crackley Bank when the collision happened.
A West Midlands Ambulance Service spokesman said: "Two ambulances, a paramedic officer and the Midlands Air Ambulance from Cosford attended the scene.
"On arrival we discovered two patients. The driver of one of the cars, a woman, was found to be in a serious condition. She received specialist trauma care at the scene before being taken to Royal Stoke University Hospital by land ambulance.
"The doctor from the air ambulance travelled with the patient to help continue treatment en route to hospital. The driver of the second car, a man, was assessed and discharged at the scene."
Anyone with information is asked to contact police on 101 or online quoting reference 85i of 7 June 2021. Alternative Crimestoppers can be contacted anonymously on 0800 555 111.