Public traffic safety early warning method and system

The invention discloses a public traffic safety early warning method and system which includes that a hardware scanning device scans scanned objects passing through a door of a bus and transmits the obtained scanning data to a processor; a first gas sampling device samples gas at the door when the scanned object passes through the door and transmits the first sampling data to the processor; the processor acquires the scanning data and processes and analyzes the first sampling data to obtain a first analysis result; when the first analysis is dangerous prompt information, the processor generates early warning information and transmits the early warning information to the terminal; the terminal displays the received early warning information and conducts early warning prompt. Therefore, automatic quick accurate early warning of bus safety can be achieved.