Gravitational lensing have become a frontier research in a short period of time thanks to its power to probe dark matter. From strong lensing, to weak lensing, and micro-lensing, this phenomenon play important roles at every scale to help us understand not only the dark matter properties but also the expansion history. Here in this talk, I would like to introduce two recent works on weak gravitational lensing and one on micro-lensing to show the power of gravitational lensing. And I will also introduce a 2.5 meter telescope co-built by University of Science and Technology and Purple mountain observatory and cast future predictions on gravitational lensing study based on the data.