Abstract: There is not a canonical algorithm of internal force and reioforcing bars of a new-type particularconcentrate spiral cantilever structure at present. In this paper, it is simplified to annular plate fixed at centreand it's strict solution wen tallies with analysis rerults by computer. This method has been applied in a projectnamed "Xiaodongshan Biluota" and good rusults had been achieved. It can be used as a reference for designingsimilar type sturcture.