The defense team is a mass self-defense autonomous organization, and its main duties include assisting public security organs to maintain social order. Under the organization and leadership of public security officers, joint defense team members participate in patrol duty, blocking cards and other tasks to prevent and stop illegal and criminal activities. They are also responsible for educating the masses to abide by laws and social ethics, maintaining public order within their jurisdiction, rounding up and intercepting criminal suspects, and providing clues for investigation and solving cases. In some cases, the joint defense team can also participate in the security of large-scale activities and major events, clean up the homeless in the receiving block, rescue people in distress, and cooperate with relevant departments to carry out other center work. However, the joint defense team has no power of investigation, trial and punishment, and has no power to restrict personal freedom. They can only assist the public security organs within the scope of their duties.