The two cars collided on the eastbound carriageway between Junction 3 for Whitchurch and Junction 2 for Wolverhampton at around 7am.
National Highwaysy said that traffic was "passing the scene via the hard shoulder", adding: "There are long delays, please take care on the approach."
Traffic is stretching back beyond Junction 3, with an ambulance and two fire engines seen heading towards the crash site.
Tweeting an update at 8.15am, National Highways said: "Both lanes 1 and 2 remain closed on the M54 eastbound between J3 and J2 Wolverhampton following a collision. Traffic continues to pass the scene via the hard shoulder. There are long delays of at least 35 minutes above usual journey times on the approach. Approach with caution."
By 8.45am, the carriageway had been reopened, but the queues had were causing 45-minute delays.
West Midlands Ambulance Service said an ambulance and paramedic officer were sent to the scene.
A spokesman said: "On arrival we discovered two male patients. One was treated for injuries not believed to be serious before being taken to New Cross Hospital. The second was assessed and treated for minor injuries before being discharged at the scene."
Shropshire Fire and Rescue Service said the crash involved two vehicles hitting the central reservation. The fire service reported that nobody was trapped in either vehicle, and that firefighters made the scene safe.
The crash comes on the first day Shropshire's train service ground to a halt due to industrial action.
Every train was cancelled on Tuesday due to Network Rail staff being among 40,000 striking workers.