The rapid expansion of the worldwide tourism industry has significantly increased energy consumption in hotels. Hence, the renovation of existing hotel buildings is relevant to achieving the energy-saving goals of the construction sector. This study takes a hotel in eastern China as an example of energy-saving renovation. First, based on a BECS energy-saving design and SPSS statistical analysis software, the energy-saving effects of renovation of building envelope (windows, walls, and roofs) are dynamically simulated, and a comparison of various renovation schemes is carried out by adopting an orthogonal experimental method and conducting a variance analysis. Second, the energy performance of the lighting and air conditioning systems is analyzed during the entire renovation process. Third, the economic environmental and social benefits were comprehensively analyzed. The results show that energy-saving renovations can effectively reduce energy consumption in existing buildings as well as the associated CO2 emissions. Specifically, the energy-savings rate of the building envelopes and the energy systems were 14%–20% and 60%–70% respectively. As for carbon emission, 947.55 tons of total CO2 emissions per year were eliminated through the renovation project. Specifically, CO2 emission reductions reach 247.65 tons per year through energy-saving renovation of building envelope, and CO2 emissions reductions resulting from the renovation of the air-conditioning system and lighting system were 220.88 tons and 479.09 tons per year respectively. Additionally, the dynamic investment payback period of the hotel energy-saving renovation project was calculated to be between 8–9 years. The demonstrates that the renovation of hotel buildings plays an essential role in benefiting the environment and the economy and social welfare.