In order to solve the problems in practical application of Building Information Modeling (BIM) as an innovative tool and production method, the author proposes a method for simulating modern buildings using the Ecotect software. This method establishes a digital BIM parametric model, the digital information technology is directly applied to the whole life cycle of the construction project, and then the effectiveness of the method is verified by examples. The result obtained is as follows: The authors’ method is designed with the assumption that Construct III is below the standard limit throughout the year, in order to meet the requirements of energy-saving design; it is recommended to change the type of external window in the engineering design scheme and make the energy consumption of buildings meet the requirements of energy-saving standards. The method proposed by the author saves about 20% of the construction cost compared with the traditional method. It is proved that the author’s method can make architectural designers correctly understand the feasibility and applicability of the Ecotect software in building energy conservation and promote BIM technology and software; BIM technology can be widely used in engineering projects, allowing architects to select the right and suitable software for various energy conservation simulations and build energy-saving building solutions.