Abstract: The coaction of scanning laser with material processed impacts the quality of parts and processing efficiency. The scanning laser energy and its distribution determine the accuracy and performance of SLS parts. The scanning laser energy and its distribution are analyzed,and influence of the relational parameter on scanning laser energy and its distribution is discussed in this paper. Then it is concluded that the relation of scanning laser energy with scanning space is nonlinear,and its distribution is associated with scanning space,and the energy and its distribution are associated with beam diameter and scanning speed,but is irrespective with number of scanning laser lines.