The invention relates to the technical field of constructional engineering management, and particularly relates to a full-life building cycle monitoring operation and maintenance method and system, wherein the system is mainly composed of a data access module, a building information model module, a geographic information system module, a data support module, a human-computer interface module, a big data analysis module and a coma information collaboration module. The method comprises the following steps: S1, establishing a three-dimensional model of each building and equipment in constructional engineering through a building information model, S2, providing basic geographic space information for constructional engineering through a geographic information system; a three-dimensional model is combined and displayed on a human-computer interface; S3, all the devices in the S1 are connected to a monitoring management platform in a human-computer interface in a unified mode through the Internet of Things; a traditional two-dimensional simulation schematic diagram monitoring mode is eliminated, a three-dimensional accurate monitoring interface is adopted for monitoring, the method is more visual compared with a method of checking drawings and turning data, real-time field positioning and marking and remote monitoring and management can be achieved through a human-computer interface module, and operation and maintenance work is simpler and more efficient.