They are the same in some degree, but the former suggests that I do not drink at home, but maybe I drink outside. The sencond is just a statement that mean when I am at home, I do not drink.

1st one represents "I drink ,but never drink at home." something like when i want to drink, i'll go out of home. 2nd one means "When I at home, I never drink" Put emphasis on different context.

Both of two are correct