As the application of Large Scale Integrated (LSI) circuits and Very Large Scale Integrated (VLSI) circuits the new test method is needed for circuit testing.Boundary scan technology can solve the problem especially for VLSI circuit testing.The principle of boundary scan is summarized.The standards of boundary scan are overviewed.Some widely used testing algorithms and their advantages and disadvantages are described.The main achievements on the application of boundary scan are analyzed.In the end the development trends of new standard research remote testing and testing method etc.are predicted which may provide a reference for one to understand the present and future of the boundary scan technology.