The　development　and　application　of　quantum　algorithms　have　exerted　a　profound　influence　on　the　design　and　analysis　of　cryptographic　algorithms.　Currently,　the　Grover　search　algorithm　and　Simon　quantum　period　finding　algorithm　are　the　most　widely　used　algorithms　in　the　quantization　of　cryptographic　analysis.　However,　as　the　quantization　of　birthday　collision　attack,　BHT　(Brassard,　H∅yer,　Tapp)　quantum　collision　search　algorithm　has　not　been　applied　in　cryptanalysis.　It　is　of　great　significance　to　study　the　BHT　algorithm　for　the　analysis　and　application　of　cryptographic　algorithms.　By　analyzing　the　multi-round　EM　(Even,　Mansour)　structure,　the　combination　of　collision　search　algorithm　and　differential　key　recovery　attack　is　studied　under　classical　and　quantum　conditions,　what　is　more　the　multi-round　EM　structure　is　attacked　with　differential　collision　key　recovery,　and　the　attack　is　quantified　from　the　perspective　of　BHT　algorithm.　The　results　demonstrate　that　the　time　complexity　of　the　differential　key　recovery　attack　on　r-round　EM　structure　decreases　from　O(2p+n)　to　O(2p+n/2)　and　the　speed　is　2n/2　times　faster　when　the　differential　probability　is　2-p≥2-n/2　as　under　classical　conditions.　In　the　quantum　conditions,　when　the　differential　probability　is　2-p＞2-n/3,　the　time　complexity　of　differential　collision　key　recovery　attack　based　on　BHT　collision　search　is　better　than　that　based　on　Grover　search,　which　shows　the　effectiveness　of　BHT　algorithm　on　specific　cryptanalysis.　©　2021,　Science　Press.　All　right　reserved.