Abstract: Sea Surface Salinity Satellite is China’s first Satellitein the marine dynamic environment series dedicated to observing ocean salinity.Aiming at the requirements of high-precision and high-stability cold-space observation for microwave payloads, this paper proposes a cold-space calibration technology. By adopting a piecewise sinusoidal trajectory planning method considering the angular velocities at the start and end points, the attitude maneuver trajectory can be accurately planned, avoiding attitude maneuver overshoot and improving the stability of attitude maneuver. Combined with the on-orbit operation characteristics of the satellite, safety designs are carried out for payload deployment, floating-point calculation anomalies and energy security to ensure the long-term stable operation of the satellite. To address the problems of high customization, long development cycle of traditional satellite control subsystem software, a modular, component-based and reusable general application software is designed, which significantly improves the efficiency and quality reliability of software development. Aiming at the problems of complex hardware architecture, high cost and poor reusability of special test equipment, a digital general verification technology is proposed. Through the test design of "generalized hardware + configurable software", the engineering requirements of rapid delivery, cost reduction and efficiency improvement are met. The on-orbit flight results show that the above designs can fully guarantee the rapid delivery and long-term safe, stable and efficient on-orbit operation of the satellite, and have the value of cross-model promotion and application.