The characteristics of business management of building electromechanical equipment installation project are professional complexity,strong technology and fast equipment updating.In view of the problems encountered in the business management in the mechanical and electrical installation of the new Taipa Ferry Terminal project at Macau,this paper analyzes the “back-to-back” principle in business management,the key points of design change and fund management,the handling of business disputes and how to replace professional subcontractors,etc.It draws the conclusion that “the engineering construction technology and business are inseparable,and technology must be subordinate to business”,and emphatically expounds the points of view on implementation of the business management in the general contracting of mechanical and electrical installation,and further confirm the conclusion that business is the leading factor and technology is the support.Only by combining the two management elements organically,can the successful implementation of the project be guaranteed.