A life-cycle performance intelligent-sensing and degradation warning system and method for concrete structures are disclosed. The warning system comprises a main control module, a multifunctional sensor module, an anti-theft module and a critical warning module. Environmental parameters in concrete are monitored by the multifunctional sensor module, and the remaining service life of a concrete structure is accurately predicted through a life prediction model according to the temperature, humidity, chloride ion concentration and pH at different depths, and a critical chloride ion concentration and a structure stress status that are dynamically obtained. In addition, during warning analysis, a targeted correction method is designed for acquired data, and temperature and pH correction is carried out for real-time monitoring data of the chloride ion sensor to further guarantee the accuracy of monitoring data, such that scientific references are provided for durability evaluation, protection and restoration of the structure, and the actual application value is high.