The invention provides a grain transportation monitoring method and a system. The method comprises steps that operation video records of a grain transportation tool acquired by video monitoring devices are respectively analyzed intelligently, a beginning video frame and an ending video frame of a transportation tool at each operation stage are positioned, and operation video segments corresponding to an operation stage are acquired; the various operation video segments are spliced to acquire a spliced video; the spliced video and a corresponding operation business identifier are associated; the spliced video can be obtained according to the business identifier, and grain transportation monitoring is carried out. The data space occupied by operation videos is reduced, the business identifiers corresponding to the operation videos are recorded, and monitoring and tracing efficiency of the full grains warehouse-in and warehouse-out process is improved.