Abstract: There are significant advantages in enhancing the performance of Earth observation platforms and reducing observation costs for Very Low Earth Orbit (VLEO) satellites. However, in the VLEO environment, the aerodynamic drag and aerodynamic thermal load caused by collisions between atmospheric molecules and the satellite surface cannot be ignored, posing substantial challenges to the satellite's on-orbit lifespan and safety. This paper first employs the Direct Simulation Monte Carlo (DSMC) method to analyze the aerodynamic drag, aerodynamic moments, and aerodynamic thermal characteristics of VLEO satellites within an orbit altitude range of 300 to 100 km, systematically studying the effects of orbital altitude, surface accommodation coefficients, and flight angle of attack on the satellite's aerodynamic performance. Subsequently, based on drag reduction optimization analyses for flat plate and conical shapes, two optimization designs for VLEO satellites, referred to as lateral side smoothing design based on surface characteristics and head shape optimization using genetic algorithm, are proposed. The feasibility of these two optimization designs is evaluated by DSMC calculations. The results indicate that at an altitude of 100 km, the lateral side smoothing design achieves a drag reduction of up to 40%, while the head shape optimization yields a reduction of 26%. Both of two optimization designs effectively reduce the aerodynamic drag of VLEO satellites, providing significant references and guidance for aerodynamic optimization design of VLEO satellites.