High　ammonia　stress,　which　inhibited　the　performance　and　stability　of　anaerobic　digestion　(AD)　systems,　is　considered　a　bottleneck　problem.　To　improve　the　performance　of　ambient　acidogenic　AD　system　under　high　ammonia　stress,　three　different　strategies　were　developed,　including　native　sludge　with　nano　zero　valent　iron　(nZVI)　addition　(SnZVI),　domesticated　sludge　enriched　with　homoacetogens　with　no　additive　(SDomesticated)　and　domesticated　sludge　with　nZVI　addition　(SDomesticated+nZVI).　All　groups　were　operated　at　ambient　temperature　(24　+/-　1　degrees　C).　Results　showed　that　ammonia　stress　restricted　the　acidogenic　rate　in　ambient　acidogenic　system　significantly.　Under　ammonia　stress,　both　SDomesticated　and　SDomesticated+nZVI　showed　positive　impact　on　acidogenesis　to　resist,　while　the　nZVI　solely　of　SnZVI　couldn＇t　relieve　the　ammonia　stress　effectively.　Compared　to　nZVI　or　domesticated　sludge　solely　added　system,　SDomesticated+nZVI　showed　highest　acidogenic　rate　under　high　ammonia　stress.　The　SDomesticated　treatment　increased　acetic　acid　and　ethanol　production　under　high　ammonia　stress　compared　to　the　SControl.　The　SDomesticated+nZVI　further　increased　the　production　of　formic　acid　and　H2　and　reduced　the　generation　of　CO2.　Microbial　community　analysis　indicated　that　the　relative　abundances　of　main　acidogens　Bifidobacterium,　Solobacterium　and　ethanol　producing　bacteria　Ethanoligenens,　increased　in　the　SDomesticated　and　SDomesticated+nZVI　groups.　Moreover,　SDomesticated+nZVI　increased　the　relative　abundance　of　relevant　functional　enzyme-encoding　genes　involved　in　the　generation　of　acetic　acid,　formic　acid　and　ethanol　and　reduced　the　relative　abundance　of　key　functional　enzyme-encoding　genes　related　to　butyric　acid　production.　This　work　could　provide　a　novel　practical　strategy　to　improve　the　performance　of　ambient　acidogenic　AD　system　under　ammonia　stress.