Focusing on the shortcomings such as long delay, high Bit Error Rate (BER), asymmetric channel in deep space communication, high redundancy and low decoding success rate of short LT codes, a new deep space data delivery strategy based on Optimized LT (OLT) codes was proposed. First, the OLT codes was given by adjusting the degree distribution function, and adopting new packet selection strategy and joint decoding algorithm. Then, a deep space data delivery strategy based on OLT codes was presented, in which the sender encoded the data file and sent it out, and the receiver got the data by decoding the encoded packets by use of joint decoding algorithm. The simulation results show that compared with LT codes, OLT codes can improve decoding success rate and reduce redundancy. Besides, compared with CFDP, the proposed strategy can effectively reduce the delay and improve the validity and reliability of data delivery, especially in the case of high packet loss rate.