I bought a home prior to my marriage- I put my husband's name on the home through a deed - now a piror debt of his has placed a lien on the house - can they legally do this if we wee not married prior to the debt ?

Yes they can. If they have a judgement against him, they can attach assets that he holds jointly. Doesn't matter when the assets were obtained.

A lien only prevents the property from being sold until the debt is settled.