This series of conferences facilitates fruitful collaborations among the world´s control system specialists from major scientific installations, such as particle accelerators, light sources, laser facilities, telescopes, tokamaks, etc. ICALECPS 2021 is hosted by Shanghai Advanced Research Institute, which is the photon science center of China, operating two large scale facilities: SSRF and SXFEL (commissioning). SSRF is the first 3rd generation synchrotron light source in China, which gives priority to original fundamental research, applied research with important application prospects and high-tech development to improve technical innovation. SXFEL is the first X-Ray free-electron laser user facility in China. It is based on a 1.5 GeV normal conducting high gradient C-band linac and contains two FEL beamline, a seeded FEL beamline and a SASE beamline, and five experimental stations.