How to manage, conflict of interest b/w boss and sub-ordinate, cause boss is always right and sub-ordinates do the work for you?

This is a tough situation and a very realistic one as well that "middle management" suffers from and deals with on day-to-day basis.

Unfortunately, there is no magic solution to these situations and the answer very much depends on the specifics of the situation itself.

The boss is always right  !!   Maybe it is wise to accept that and deal with it on this basis, but try always to protect yourself from boss mistakes when/if they happen, because many bosses will wash their hands off, tend to forget what they asked for, and may very well treat you as a sacrifice goat when the shit hits the fan (excuse my language) !!

it is also also a "corporate culutre thing" that puts the rules and guidelines to what is acceptable and what is not in dealing with conflicts (conflict management/resolution), sagregation of duties ( to avoind such conflicts from the beginning) and how to deal with crisis (crisis management) internally and externally.

It is also an issue of "management practices" regarding clear definition of ownership, authority, accoutabilty, and empowerment at the different levels of the work hierarchy.   

Middle management is very of then the "make-or-break" reality check point in organizations where success or faiure of the organization shows off.    Middle management capability/competency in dealing with these situations is very very important with proper skills development, competency assessment, good negotiation and deleegation practices ... etc .. etc.

If you need further help with this answer, let me know !