The smash took place in the southbound lane between junction 23 and 22, near Ashton-in-Makerfield in Greater Manchester.
It is understood the collision involved four cars and one van.
According to traffic reports one of the cars has set on fire.
Traffic bosses had shut all lanes southbound and two lanes have been shut northbound.
At approximately 07:45am, traffic on the southbound M6 was able to pass the scene of the incident on the hard shoulder.
Queues are currently stretching back from between junctions 23 and 22 to junction 26 for the M58.
Traffic is also building on the eastbound M58 for the M6.