Background <p>Colorectal cancer (CRC) incidence and mortality are rising in China, with high body mass index (BMI) established as a significant risk factor. However, comprehensive evidence regarding the BMI-attributable CRC burden in the Chinese population remains limited.</p> Objective <p>This study aims to analyze the trend of CRC burden attributable to high BMI (BMI ≥ 25 kg/m²) in China from 1990 to 2021 and to predict its development from 2022 to 2035, in order to provide a scientific foundation for the formulation of public health policies.</p> Methods <p>We analyzed data from the Global Burden of Disease Study 2021 (GBD 2021) to assess the BMI-attributable CRC burden in China from 1990 to 2021. Temporal trends were analyzed using Joinpoint regression models. Future projections through 2035 were generated using Bayesian age-period-cohort (BAPC) modeling. The Das Gupta method was used to explore the contribution of population growth, aging, and epidemiologic factors to these burden changes.</p> Results <p>From 1990 to 2021, China’s BMI-attributable CRC burden increased substantially, with ASMR and ASDR rising at annual rates of 2.393% (95% CI 2.306–2.481) and 2.305% (95% CI 2.188–2.422), respectively. The mortality and disability-adjusted life years (DALYs) rate both increased with age. Males showed higher burden rates in most age groups. Projections indicate continued increases in ASMR (2.43% annually) and ASDR (2.44% annually) through 2035. Epidemiological factors were the primary drivers, contributing 99.73% to mortality changes and 44.81% to DALYs changes.</p> Conclusions <p>The BMI-attributable CRC burden in China shows a concerning upward trajectory that is predicted to continue, with epidemiologic factors playing a major role. Urgent public health interventions targeting obesity prevention, lifestyle modification, and expanded CRC screening are needed to mitigate this growing burden.</p>