In the legal framework governing the guardianship of adults with intellectual disabilities, the conflict between autonomy and guardianship primarily arises from the evaluation of the individual’s decision-making capacity and the corresponding handling of their rights. The “one-size-fits-all” provisions in current laws often overlook the autonomy of adults with intellectual disabilities in key areas of life such as healthcare, economic, education, and social particiation. This leads to excessive intervention by guardians, resulting in an imbalance and injustice in the protection of their personal and property rights. To address this issue, legal reforms should be implemented to ensure that adults with intellectual disabilities have decision-making and participation rights. A decision-support system should be established to provide necessary assistance while maximizing their right to make autonomous choices. Furthermore, the state should intervene with appropriate public authority and develop more detailed plans for safeguarding autonomy according to different situations, thereby improving the guardianship system and ensuring more comprehensive and balanced legal protection of the rights of adults with intellectual disabilities.