The key laboratory of quantum optics of the Chinese academy of sciences was founded in December 1989. In recent years, we have carried out many important scientific research and engineering projects such as the national manned space program, Chinese national natural science foundation, and States’ Key Project of Research and Development Plan. The laboratory mainly engaged in the frontier scientific researches in space-borne and ground high precision atomic clock, time-frequency transfer, cold atom physics and its application, the intensity correlated imaging which combines with optical imaging and modern information theory etc. In March 2002, we first observed BEC phase transition of rubidium atom in China, and then we first achieved a BEC on an atom-chip in 2008. In 2010, we first reported guiding cooled atoms in a high field seeking magnetic state. On September 15, 2016, our space cold atom clock, which is currently the only cold atom clock in orbit in the world, was launched with Tiangong-2 space station. The measured center line width of the Ramsey fringes is less than 0.8Hz, the stability reaches E-16 in one day (that is, the error is 1 second in 30 million years), which improves nearly one order of magnitude above the accuracy of current space-borne clock. In 2017, we developed the first domestic engineering prototype of integrating sphere cold atom clock, the long-term stability is better than 2E-15. The laboratory firstly approved that the classical thermal fields can be used for quantum imaging in theory, and then developed the first experimental test prototype for airborne laser 3D intensity correlated imaging, demonstrated the first X-ray microscopy with intensity correlated imaging , developed the field test prototype of single exposure multispectral intensity correlated imaging. The laboratory has obtained demonstration results in the engineering application and networking of fiber time and frequency transfer.