It is difficult to solve the problem of large amounts of lines open and short faults. The boundary scan technique is applied to the line test. So the connection between lines is changed into wire between large scale integrate circuit. The correction is judged by transforming and sending signals. This test equipment can solve the problem of line testing by experiment. The equipment can find wrong wire exactly for a short duration. The result is exact and reliable. The equipment satisfies the needs of large amounts of line test. It provides a good reference for the development of boundary scan.