In view of the existing multi-pulse position modulation (MPPM) schemes in deep space optical communication, the constellation points have a low utilization rate and the location selection needs to be optimized. By comparing the average hamming distance between constellation points of different MPPM schemes and the probability of signal pulses in adjacent time slots, an MPPM constellation mapping scheme with stronger anti-delay jitter capability is proposed. Based on the existing serial concatenated pulse position modulation(SCPPM) decoding algorithm, a SCMPPM iterative decoding algorithm is derived. Simulation results show that the performance of this scheme is better than the existing schemes. It not only enables the communication system to maintain a high information transmission rate, but also reduces the probability of inter-symbol interference(ISI) and inter-slot interference(ITI) between MPPM constellations, thereby improving the anti-delay jitter capability of communication system.