Abstract: LEO satellite system has received extensive attention and development in recent years. The satellite has low orbit height, short transmission delay and small path loss, and can provide services for miniaturized user terminals. But at the same time, it also has the problems of large path difference in single satellite coverage area, uneven satellite service distribution and large working dynamic range. Aiming at these problems, a beam optimization design method for LEO satellites is proposed, which adopts earth matched beam design to achieve better link quality and coverage efficiency. In the downlink beam design, the phase only weighted optimization design method is adopted to achieve the adjustment ability of single beam power from 0% to 100% on the basis of meeting the beam gain requirements and inter beam C/I. In view of the characteristics that the output power of the transmitting module works in the fallback state for a long time due to the change of the LEO satellite mobile communication service with time, a satellite adaptive power amplifier power followup technology is proposed to realize the matching adjustment between the change of the service volume and the optimal efficiency of the power amplifier through the satellite service processor, which effectively improves the average efficiency of the power amplifier and reduces the average power consumption and heat consumption of the antenna.