Abstract: Measurement of the effect of industrial output changes on carbon intensity can provide guidance for industrial structure adjustment plan which is based on carbon emission reduction targets. Based on input-output theory, a system dynamics model is established, on the basis of which, dynamic effect of main industrial sectors changes on carbon intensity is analyzed. From the two aspects of investment structure and consumption structure, it explores the effective ways to realize the carbon emission reduction targets of China's main industries. The results showed that: from the current effect, manufacturing, electricity, heat and water production and supply industry, mining industry output increased carbon intensity; from the dynamic perspective, if the output value of animal husbandry and fishery, mining, manufacturing, construction, transportation, storage and postal industry, wholesale and retail, accommodation and catering industry, real estate, leasing and business service industry increases 1%, carbon intensity will gradually decrease; from the perspective of carbon intensity trend, the force of industrial sectors' output increase on carbon intensity will gradually stabilize. The improvement of the effectiveness of industry output changes on carbon emissions should rely on investment policy.