Abstract: Objective Based on data from the Global Burden of Disease (GBD) 2023 estimates, this study systematically analyzed the disease burden and long-term trends of type 1 diabetes mellitus (T1DM) in China and globally from 1990 to 2023, aiming to provide evidence-based support for the development of T1DM prevention and control strategies. Methods We extracted data on the incidence, prevalence, mortality, and disability-adjusted life years (DALYs) of T1DM in China, globally, and across regions with different sociodemographic index (SDI) levels from the GBD 2023 database for the period 1990–2023. The age-standardized incidence rate (ASIR), age-standardized prevalence rate (ASPR), agestandardized mortality rate (ASMR), and age-standardized DALYs rate (ASDR) were calculated. Joinpoint regression models were employed to estimate the average annual percentage change (AAPC) and analyze long-term trends, with stratified analyses by sex and age group. The Das Gupta decomposition method was applied to decompose changes in T1DM burden into three components: population growth, population age structure changes, and epidemiological changes, to evaluate the contribution of each factor. Results In 2023, the global ASIR of T1DM was 3.67/100 000, an increase from 3.16/100 000 in 1990 (AAPC = 0.46%); over the same period, the ASIR in China rose from 1.86 to 2.63 /100 000 (AAPC = 1.08%). The global ASPR increased from 95.06 to 103.71 /100 000 (AAPC = 0.28%), while the ASPR in China increased from 51.95 to 62.29 /100 000 (AAPC = 0.55%). In contrast, theglobal ASMR declined from 0.90 to 0.65 /100 000 (AAPC = –0.80%), and the ASMR in China declined from 0.59 to 0.19 /100 000 (AAPC = –3.30%). Both global and Chinese ASDR showed declining trends. The highest ASIR was observed in high-SDI regions (7.95 /100 000) with a relatively rapid increase, while low-SDI regions had the highest ASDR at 43.97 /100 000. Sexstratified analysis revealed that ASIR remained consistently higher in males than in females, but females experienced a greater decline in mortality. Age-stratified analysis showed that the incidence peaked in the 0~14 age group, with the most prominent increase observed in those aged ≥60 years. Decomposition analysis indicated that the reduction in T1DM deaths and DALYs in China was primarily driven by epidemiological changes (contributing +184.43% and +157.85%, respectively); whereas the global increases in incident cases and prevalent cases were predominantly driven by population growth (contributing +77.33% and +64.69%, respectively). Conclusions From 1990 to 2023, both China and globally exhibited a trend of "rising incidence and prevalence alongside significant declines in mortality and DALYs" for T1DM. The sustained increase in the number of surviving T1DM patients will impose continued pressure on the prevention and management of long-term complications and the allocation of healthcare resources. Future efforts should strengthen the collection of localized surveillance data, with a focus on early diagnosis and treatment of T1DM in children, comprehensive management of chronic complications in middle-aged and elderly patients, and continued improvement of insulin accessibility in low-SDI regions.