Response to viewer question "Would you favor legalizing the medical and recreational use of cannabis at the federal level?" in WLOS Debate (Starts at 45:02), he says he supports the federal government getting out of the way. 

He has not cosponsored legislation to do so. 

Response to 2020 NC Family Policy Council's question "Should Congress legalize the use of marijuana for medical purposes?" YES

Article about Cawthorn

https://www.washingtonpost.com/politics/2021/02/27/making-madison-cawthorn-how-falsehoods-helped-propel-career-new-pro-trump-star-far-right/