Abstract: In order to reduce high time complexity and long time of star image recognition of traditional triangle star pattern recognition algorithm commonly used in star sensor, an improved fast star pattern recognition algorithm was proposed.The algorithm preserves star diagonal distance and angular distance tolerance set by constructing an array of two-dimensional linked list, which avoids repeated calculation and repetitive searching process of star diagonal distance. Then a new star matching method by using hash table is constructed, which can reduce the number of star pairs of angular matching and time complexity of triangular star map recognition significantly. Experimental results show that starred recognition time of improved algorithm is reduced by 70% compared with traditional triangle star pattern recognition time under different star perturbations and different observation star numbers, which is significant to improve the attitude updating frequency of star sensor.