As small satellite constellations are becoming gigantic， the conceptual study on the low-orbit large-scale constellation based on remote sensing satellites and its phased deployment scheme are presented. First， factors such as the ideal number of accommodating satellites， interactions， and the orbital control accuracy in low orbit， the magnitude analysis of low-orbit large-scale constellation are incorperated to clarify the constellation scale. Second， the artificial potential function method is used to extend the satellite individual control to the overall density migration of the constellations， thus a specific density distribution is achieved to meet the mission requirements. Third，combined with the characteristics and construction capabilities of constellation of remote sensing satellites， a hybrid constellation configuration based on Sun-synchronous orbits， low inclination orbits and highly elliptical orbits is proposed. According to the short， medium and long-term requirements， the constellation is deployed in phases. Simulations verify the advantages of the low-orbit large-scale constellations.This study provides certain references for the design and control of mega-constellations in the future.