Statistical data of the basic data about Danjiangkou city's houses are obtained through documents collection and field investigation. On the basis of the data, we used probability analysis method of seismic vulnerability to make prediction of earthquake damage to buildings in Danjiangkou city. Prediction results show that Danjiangkou city has already reached basic requirements of seismic fortification VI degree, which means that the probability of a catastrophic failure is very small while suffers a VII degree earthquake, but moderate damage will likely occur widely, and lead to greater economic losses and casualties. The economic analysis of anti-seismic measures indicates that Danjiangkou city could achieve three levels of anti-seismic fortification target if about 6% of building investment was increased. Meanwhile, this paper puts forward some anti-seismic measures and advices for the government planning and management of earthquake prevention and disaster relief.