The traditional routing spectrum allocation(RSA) algorithm in elastic optical network(EON) mostly considers the hop number or spectrum resource occupation, and lacks the effective utilization of time domain and adjacent link information. This paper proposes a multi-dimension-aware RSA algorithm combined with prediction, which predicts the time information of future services through back propagation neural network for the known duration of services time, spectrum and adjacent link resource occupancy are considered. The simulation results show that compared with the traditional RSA algorithm, multi-dimension-aware RSA algorithm can effectively reduce the bandwidth blocking rate.