Based　on　the　upper　bound　limit　analysis,　the　multi-log　spiral　failure　mechanism　for　earth　retaining　structures　under　horizontal　seismic　loads　was　constructed,　which　could　introduce　the　nonlinear　strength　criterion　into　stability　analysis　without　any　linearization　technique.　By　calculating　various　external　work　rates　and　the　internal　energy　dissipation,　the　energy　balance　equation　was　established,　and　the　active　earth　pressure　formula　required　for　the　retaining　structure　to　be　in　a　critical　stable　state　was　derived.　With　the　application　of　a　genetic　algorithm　and　particle　swarm　optimization,　the　optimal　upper　bound　solutions　of　active　earth　pressure　coefficients　were　obtained.　The　validity　of　the　research　results　was　verified　through　comparative　analysis.　This　paper　provided　diagrams　of　the　active　earth　pressure　coefficients　required　for　earth　retaining　structures　to　maintain　a　critical　stability　state　under　different　parameters.　The　influences　of　seismic　load,　slope　inclination　angle,　soil　strength　tension　cutoff　(TC),　and　the　delta/phi　ratio　were　investigated.　By　investigating　the　design　charts,　the　active　earth　pressures　applicable　to　practical　engineering　can　be　obtained,　which　provide　a　theoretical　basis　for　the　preliminary　design　of　retaining　structures　in　earthquake-prone　areas.