The main functions of Beijing Municipal Security Bureau are as follows：
I. Implementing the laws, regulations, rules, and policies on public security of the state, studying and drawing up the drafts of local laws and regulations, government regulations and policies and measures of Beijing Municipality, and organizing the implementation thereof.
II. Keeping up to date with the situations that affect political stability and endanger domestic security and social order, formulating relevant countermeasures, and being responsible for organizing the implementation thereof.
III. Preventing, stopping and investigating illegal and criminal activities, undertaking anti-terrorism and anti-riot responsibilities, dealing with public security cases and incidents, administering assemblies, processions and demonstrations in accordance with the law, administering special trades and dangerous goods such as guns and ammunition and controlled knives, and carrying out safety supervision on large-scale mass activities in accordance with the law.
IV. Maintaining traffic safety and traffic order in Beijing and dealing with traffic accidents.
V. Organizing the implementation of fire control work and implementing fire control supervision; undertaking the specific work of Beijing Municipal Fire Safety Emergency Headquarters.
VI. Working as the security guard of the leaders of the Party and the state and important foreign guests in Beijing.
VII. Managing household affairs, nationality, entry and exit affairs and foreign national's residence and travel in Beijing according to law.
VIII. Guiding and supervising the public security work of state organs, social organizations, enterprises and public institutions and key construction projects in Beijing, and guiding the public security work of mass organizations.
IX. Being responsible for the security of the public information network in Beijing.
X. Being responsible for examining and approving the investigation of criminal cases according to the law, request for arrest, transferring for investigation and prosecution, cases of detaining for reeducation, as well as cases of administrative punishment and administrative coercive measures; handling cases of administrative reconsideration, state compensation and response to administrative litigation according to the law.
XI. Executing punishment on criminals sentenced to public surveillance, criminal detention, deprivation of political rights and criminals serving the sentence outside the prison; supervising and inspecting criminals who have been granted suspended sentences or parole; administering places for lockup detention, compulsory isolation for drug rehabilitation, detention for reeducation, medical treatment in prisons, etc.
XII. Leading the public security fire control and police forces in Beijing; being responsible for the armed police forces in Beijing to perform public security tasks and relevant practices in Beijing.
XIII. Being responsible for the scientific and technological work on public security, and the upgrading of the public security information and communication technology, criminal technology, etc.
XIV. Formulating and implementing the rules and regulations for the administration of the teams of the bureau; being responsible for the work related to team administration such as organizations, officials, human resources and talents; implementing education and training for all police officers of the bureau; being responsible for the publicity work concerning public security; carrying out supervision and auditing of police affairs, and investigating and punishing cases in violation of the law or the discipline.
XV. Being responsible for the work concerning the bureau's public security funds, equipment, infrastructure, general assets, health of police officers, logistics services and other police security work.
XVI. Undertaking the specific work of Beijing Municipal Anti-terrorism and Criminal Case Emergency Response Headquarters.
XVII. Performing other matters assigned by the municipal government.