Carbon accounting for layer hen operation has remained underdeveloped at the township scale in North China. There is an ever-increasing need for precise mitigation planning for the high production intensity. In this study, the whole-chain carbon emissions were quantified to identify the spatial hotspots for the mitigation potential of coordinated low-carbon technologies in a typical layer-hen-intensive township in Quzhou County, Hebei Province, China, during 2023–2025. A hybrid life cycle was assessed to combine with the Intergovernmental Panel on Climate Change greenhouse gas accounting framework. The boundary also covered feed crop production, feed processing and transport, layer rearing, manure removal and storage, as well as manure treatment with resource utilization. Carbon emissions were estimated, according to three consecutive years of field survey data from more than 300-layer-hen households, together with parameters from livestock studies and emission factors from the Ecoinvent version 3.9 database. Annual emissions were calculated per kilogram of eggs and per bird. Three scenarios were selected, including the baseline, multiple single-factor optimization, and an integrated optimization. A series of experiments was conducted to evaluate the independent and combined mitigation of breed improvement, feed reformulation, housing upgrades, manure treatment, and composting optimization. The results showed that there was an outstanding transition towards intensified production. The number of farming entities decreased from 382 to 310, whereas the standing population increased from 5.80 to 6.90 million, indicating a shift towards fewer but larger operations. The total annual carbon emissions declined from 42600 to 31200 t of carbon dioxide equivalent, rather than herd expansion, with a cumulative decrease of 26.8%. Carbon intensity per kilogram of eggs decreased from 0.92 to 0.78 kilograms of carbon dioxide equivalent, while annual emissions per bird decreased from 25.3 to 23.5 kg of carbon dioxide equivalent. The production efficiency was more than offset by the upward pressure from inventory growth. Spatial patterns also changed at the village scale. In 2023, high-emission villages were concentrated in the central and western parts of the township, with the villages emitting over 7000 t annually. In 2024, the hotspot area contracted markedly, and by 2025, most villages shifted to lower emission levels, below 4000 t per year. There was a transition from clustered high-emission hotspots to a more evenly distributed low-emission structure. Emission-source analysis showed that the feed process and manure treatment dominated the carbon footprint. Feed production and processing contributed about 30% of total emissions, manure removal and storage accounted for about 25%, and feed cultivation contributed about 24%, whereas transport contributed less than 2%. Feed processing and manure treatment declined by 38% over the study period, indicating the largest total reduction. Decomposition analysis indicated that the high efficiency was the leading driver of emission reduction, followed by structure optimization with scaling-up and intensification, while herd expansion remained the main factor increasing emissions. Scenario analysis further revealed that there was considerable but uneven mitigation. Post-farm manure delivered the greatest standalone reduction potential, with cumulative independent contributions of 40%. On-farm measures contributed 17%, and pre-farm interventions, especially feed optimization, contributed 16%. All optimal measures were combined in the production chain. The maximum integrated mitigation potential reached 52%, avoiding the overestimation from directly summing single-factor effects. Overall, the carbon accounting at the township scale can be expected to effectively capture structural and spatial dynamics of carbon emissions in layer hen production. The most effective pathway can be identified to coordinate the feed systems, production efficiency, and manure treatment. The finding can also provide a strong reference to reduce carbon emissions for the low-carbon transition of the layer hen industry in North China.