In order to deepen the understanding of fatigue cracking of orthotropic steel bridge decks and fatigue crack repair technologies, the characteristics of fatigue cracking in steel bridge decks were first explained, and then applications and researches of stop-hole method, adding plates method, hot repairing method, mechanical repairing method and composite bridge deck retrofit method were introduced through literature investigation. And the repair mechanism and applicability of various repair methods were discussed. Finally, the application of smart materials shape memory alloys (SMAs) in the future crack repair of steel bridge decks were proposed. The research results show that fatigue cracking repair of steel bridge decks is restricted by special site environment such as heavy traffic volume, large number of welds and narrow operating spaces, targeted repair works need to be carried out according to different crack characteristics. The proposed shape memory alloy repair method is forward-looking in the repair of fatigue cracks in steel bridge decks. The SMA-CFRP composite patch utilizes the combination of the prestress generated by SMA wire and the stiffness provided by CFRP to further strengthen the inhibition effect on crack development. The use of pasting iron-based SMA plates also has the advantages of easy construction and low cost. The SMA patching method can provide a new idea for repairing fatigue cracks of steel bridge decks and be expected to prolong the service life of steel bridge decks.