The main objective of this paper is to develop an efficient satellite digital beam-forming (BF) method that can provide user specific desirable signal-to-interference-plus-noise ratio (SINR) or data rate for each user in each zone. And a massive multiple-input multiple-output (MIMO) communications system model and its favorable channel propagation condition are assumed (i.e., channel independence among all channel coefficients from transmitter antenna elements to receiver antenna elements). Then, this paper derives a desirable user-specific BF expression. And the numerical results indicate that the user-specific SINRs can be achieved satisfactorily with the proposed method. However, in practice, the satellite channel may not meet the channel favorable propagation condition due to the known key hole effect. In future, it is desirable to study a BF method under a keyhole channel condition.