How to know a supervisor's working style before joining his group?
...never disturb to other colleagues. When I discussed with other colleagues...


Good for you!


  My question is how would I know about these things before joining his group? 


By talking with other members of the group, away from faculty, during your interview visit (or some other time before accepting the offer).

Conversations with students outside the professor's group would also have been useful. Also with the clerical staff. Even if unhappy group members themselves are hesitant to talk with strangers, for fear of reprisal, people know who the unhappy research groups are.

If the professor didn't actively encourage such conversations, that's already a red flag.