The Bavarians are two points clear at the top with nine points from three league games, and have now scored a league-record 15 goals in their three games even though top striker Robert Lewandowski left this season to join Barcelona.
Bayern went on a first-half rampage, scoring four times in 38 minutes to kill off the game.
"We are not setting ourselves any limit and are trying to deliver performances such as these as well," Bayern coach Julian Nagelsmann said.
"The energy currently in the team was not always there in such a way last season. That's something very comfortable to know. In the second half we still tried to win the game and solidify our plays.
"Every player played really well. It won't be easy picking a team for next weekend."
The visitors took a fourth-minute lead through Leroy Sane with their first attack of the game, and new signing Matthijs de Ligt got onto the scoresheet with his first-ever effort on goal for Bayern, heading in a corner at the far post in the 25th.
Kingsley Coman's shot from close range after Bochum failed to clear just past the half-hour mark made it 3-0 and all but put the game beyond doubt, before Mane completed the first-half frenzy with his second goal of the season - a low shot from a tight angle in the 42nd minute.
Bayern eased off the gas after the break, but the Senegal international added another with a penalty on the hour.
Cristian Gamboa, under pressure from Sane, scored an own goal, piling further misery on the hosts who then saw substitute Serge Gnabry make it look so easy when he thundered in a low shot off the post to make it 7-0.