In the reform of state supervisory system, there is a dispute over whether the supervisory commission should be given the power to investigate duty-related crimes and the scope of the functions and powers of the supervisory commission. The judicial system in different countries varies, so do the jurisdiction over criminal cases and the power to investigate duty-related crimes. In some countries, the investigation power is exercised by the police, while in others, it is exercised by prosecutor’s offices or specialized organs. The above differences can often be attributed to the differences in legal culture, procedural mode, characteristics of duty-related crimes, the severity of corruptions, investigation capacity, public trust, etc. With the establishment of the supervisory commission, the power to investigate duty-related crimes has been transferred from procuratorial organs to a specialized agency. Against this background, Singapore’s Corrupt Practice Investigation Bureau, Hong Kong’s Independent Commission against Corruption, and Macau’s Commission against Corruption have special significance to China. In accordance with the principles of the rule of law and human rights protection, the supervisory commission should be given the powers necessary for fulfilling its duties, but not all the powers necessary for the fight against corruption. The investigation power of the supervisory commission should not be the simple addition of the powers of existing anti-corruption agencies, but should be constructed by taking the current Chinese laws as the basis and carefully drawing on the experiences of Singapore and other countries as well as international standard of criminal justice. In the reform of the state supervisory system, the one-sided thinking of “transferring power but not rights” should be avoided and the mechanisms for supervising and checking the investigation power of the supervisory commission should be improved.