In recent year the research field of the combinatorial testing, which can roughlybe divided into two kinds including pair-wise coverage and multi-wise coverage. a lot of scholar try to use various strategies to generate test data automatically. In order to weight the generated test set, the generated test data must satisfy certain criterion. But these combinatorial strategy neglected the flexibility of using on the practice. Considering software testing from the practice, which often be restricted by the cost. For this reason, how to obtaint the greatest testing benefits under the limited cost must be considered on the parctice. But in the extant combinatorial strategy, there is no flexible use. In other words, we must testing test set totally. Therefore, there is very great restriction to exist on using the test data generated by the extant combinatorial strategy on the practice. So, this paper proposes a flexible combinatorial strategy based on CSP, which allow users to do the most valid testing under the limited cost, which also allow users join the constraints that needs at any time during the testing process, revise the test data that we produced dynamically. The experimental result indicate that our method perform well, it can avoid including the test data whether some users think the interests less or unnecessarier, in order to achive the greatest testing beneifts.Further, we can achive the goal of reducing the quantity of testing data.