The framework of the assistant decision support system of cross-regional rural labor flow is established, the system combines the cross-regional rural labor flow with DSS, which provides the leaders with the maximum assistant decision-making function in the regulation and guidance of rural labors as well as in relevant programs. The assistant decision support system functions are discussed, the function modules of this system are introduced from four aspects, including the analysis of labor flow, the prediction of labor flow, the regulation of cross-regional flow and the configuration of decision support system; based on the data base obtained from dynamic tracking of the migrant workers and combining other data sources, the data warehouse model is established, for example, in the analysis of the labor migration times, a star multi-dimensional data model is designed from the time dimension, place dimension, the type of work dimension, accompaniers dimension and so on; the trans-regional flow of rural labor force is analyzed and predicted by using OLAP from the labor’s migration times, migration places and other various perspectives. The operation principles of the assistant decision support system of trans-regional labor flow are introduced, it is pointed out that the system serves the policy-makers of the regulation of labor flow and other relevant enterprises, the system will play an important role in the tracking monitoring and cross-regional regulation of the rural labor flow.