The invention discloses a distributed type POS data reliability transmission system and method. The method comprises the steps of data obtaining, data processing and data sending. Data obtaining achieves data caching and caching data receiving; the data processing comprises the steps that firstly, data classification is achieved through identifiers in an analysis data package, then priority is judged, a priority interrupt request is processed, data integrity and data structure correctness are checked through data verification, and finally data are packed; data sending comprises the step that data are sent to a receiver by selecting different interface modes according to different data types. Multiple data sources are classified and logically judged, data real-time performance and reliable transmission are achieved through data priority judgment and data verification, and the system and method have important practical significance to implementation of integrated research and development of measurement of a distributed POS.