The existence of gravitational wave had always been a mystery since the appearance of LIGO, the most ambitious project ever funded by National Science Foundation (NSF). This huge science facility is constructed by two dependent  interferometers located in  Livingston, America and  Hanford, America. LIGO discovered the gravitational wave of a merging Neutron star binary in 2015 with the joint effort of thousands of scientists, and this extraordinary facility is still working to discover the secret of the mysterious universe. This passage will discuss the State-of-the-art of LIGO and the future of the gravitational wave discovery technology.