By taking the Kiewitt cable domes which contain multiple overall selfstress modes as the research objects，this paper deals with the improvement of ratio-updating method for forcefinding analysis of cable domes with single overall selfstress mode and proposes a new approach to forcefinding analysis of Kiewitt cable domes，with its applicability being validated by examples later． Moreover，the key members are designated and prestressed to perform an iterative computation，and，by using the mode error analysis method based on the leastsquares，a comparison of the results respectively obtained by the proposed method and the singular value decomposition method is carried out． The results show that，as compared with the singular value decomposition method，the proposed improved ratio-updating method possesses high accuracy and helps to obtain overall feasible selfstress modes with clear meaning in the mechanical concept of cables in tension and struts in compression，thus providing a new idea and solution for the prestress determination of cable domes．