Autonomous navigation supported by inter-satellite ranging and communication with inter-satellite links(ISL)is the trend of satellite navigation system development.By controlling the direction of phased array antenna flexibly,the agility link can achieve more information from other satellites.However,the efficiency of communication is affected at the same time.In this paper,we describe the data transfer problem when the data is split into several datum units whose hops are limited.We investigate the computational complexity of the problem firstly and it is proved to be an NP-Complete problem.Then we propose a linear programming model for solving the problem.At last,we show that the problem is polynomial solvable when the number of datum units or the number of recipient nodes is equal to 1.The research in this paper is valuable for solving the data transfer problem in the navigation satellite network based on agility link.