Abstract: The carbon emissions peak was projected for Gansu Province which is mainly characterized by high energy-consuming industries and fragile ecology. Based on the analysis of the current situation, the carbon emissions in Gansu are divided into seven sectors, i.e. electricity, heat production and supply industry, ferrous metal smelting and rolling processing industry, petroleum processing, coking and nuclear fuel processing industry, non-ferrous metal smelting and rolling processing industry, non-metallic mineral products industry, chemical raw materials and chemical products manufacturing and transportation industry. The sub-sectors with largest carbon emission was chosen for each key energy-consuming sector, including electricity, heat industry, iron and steel industry, oil processing industry, aluminum and magnesium industry, cement industry, ammonia industry, and transportation industry. Then, the system dynamics models of sub-sector carbon emissions were established through Vensim PLE software, and eight different scenarios were set using scenario analysis method, being respectively fast-slow scheme, middle-slow scheme, slow scheme, fast-middle scheme, middle scheme, slow-middle scheme, fast scheme, middle-fast scheme, to forecast the carbon emissions peak in Gansu Province. The results show that the peak of carbon emission is 209-429 million tons, it will appear in 2028-2045. In consideration of the peak value, peak occurrence time and current development situation, middle scheme is the optimal way for achieving carbon emissions peak. According to the forecast results, it was proposed that Gansu Province should increase the industrial structure adjustment, energy structure optimization and production technology improvement.