As the atrium have significant impact on the building environment, it can remarkably improve the ventilation and lighting conditions and reduce the energy consumption of buildings. However, in practical engineering, due to thermal environment factors in the atrium are excessive and complex, the traditional calculating air-conditioning load method - cooling load coefficient method, based on the lumped parameter concept, can not describe the distribution of temperature and load in a tall building in the atrium accurately, at the same time the designer run short of quantized analysis tools, the results of design and organization of atrium thermal environment control are not very satisfactory. In this paper, temperature and load distribution of the atrium and corridors in an tall office building in Chengdu were simulated,according to the results the load transfer rule of typical tall office building atrium are analysed. A reference for the air-conditioning load calculation on the same court buildings with atrium is provided.