Based on arch-cantilever method and 3D finite element method, the stress of Shigaoshan concrete arch dam was analyzed under 5conditions. According to the calculation results, the dam body is divided into 3zones on the basis of closing arch for grouting:the dam body under the elevation of 1119.0m is zone 1, the joint closure temperature is 14.3℃; the elevation of the dam body between 1119.0to1130.0meters was zone 2, the joint closure temperature is 12℃; the dam body above the elevation 1130.0m is zone 3, the joint closure temperature is 6.5℃.