Disclosed are a satellite power transmission system and a communication method. The satellite power transmission system includes: a reference value determining unit determining reference values of signal to interference ratios for each beam coverage of a multi-beam satellite network system; an interference amount determining unit determining an interference amount for each beam coverage of the multi-beam satellite network system; a signal power determining unit determining signal power corresponding to each beam coverage based on the reference value determined by the reference value determining unit and the interference amount determined by the interference amount determining unit; and a signal power allocating unit allocating the signal power determined by the signal power determining unit to each beam to communicate with each earth station.