Micro-bolometer using double sacrificial layers with smaller pixel size and higher resolution has been a new trend for microbolometers. Optical design and simulation of microbolometer with double sacrificial layers were analyzed in this article. Also, the manufacture, test and optimization of doule layer structure were discussed. The micro-bolometer cell structure models were constructed and simulated with Intellisuite software. The devices with and without umbrella structure were compared in this paper. The models of different structure and manufacture conditions were simulated with Intellisuite, such as the thickness of micro-bridge, the width of legs and the residual stress of thin films.