For finding out and solving the error and difference among multi data source, research on data enhancement method based on data source analysis. Put forwards 2 concepts about system conflict mode and minimum update sequence. The minimum update sequence is the compact representation of conflict among multi data source, operation sequence of the update sequence can recognize the dependency relationship among conflict, and put forward 2 algorithms for finding out minimum update sequence: greedy transformation algorithm and transformation approximate algorithm, and verify them by the test. The verification results show that 2 algorithms are effectively, it can help people carry out quality evaluation of data source and data value.