The present disclosure relates to a turbo compound system for a vehicle which recovers emission gas energy of an engine, and particularly, to a turbo compound system for a vehicle which may recover emission gas energy and provide the energy to various auxiliary devices for a vehicle in various forms. In addition, the present disclosure relates to a turbo compound system for a vehicle in which recovered emission gas energy is transferred directly to auxiliary devices for a vehicle without passing through a crank shaft for a vehicle, thereby preventing deterioration of fuel efficiency or output reduction, and simplifying facility and control.