Abstract: A new star identification algorithm is proposed based on starlike mappings pattern for the problem of secondary planet autonomous attitude determination.This algorithm directly uses star angular distance as matching feature.It firstly fixes on bright star in image by comparing magnitude as central star,then constructs radicalized star pattern at the center of it,secondly it gets guide stars using angular distance matching.Lastly it sums up the times the guide star appears,the guide star which has most appearance times will correspond to the central star in the image.Experiment demonstrates that star catalog constructed by this algorithm is little,and there is no magnitude participating in matching,So it is unacted on magnitude error.Compared with traditional polygon angular matching algorithm,this algorithm has advantage on velocity,successful identification,reliability.