The　negative　temperature　coefficient　(NTC)　thermistor,　known　for　its　high　sensitivity　and　rapid　response,　plays　a　crucial　role　in　various　sectors　such　as　the　national　economy,　military,　and　aerospace.　Linear　NTC　thermistors　can　simplify　circuit　design,　but　most　linear　NTC　thermistors　used　today　use　expensive,　heavy,　and　harmful　metals.　As　such,　researching　environmentally　friendly　NTC　thermistors　with　linear　temperature　resistance　characteristics　is　crucial　for　environmental　protection　and　advancement　of　high-performance　electronic　ceramics.　This　paper　discusses　the　synthesis　of　environmentally　friendly　linear　thermistor　materials　in　the　xAl2O3-(1-x)ZnO　composite　using　the　solid-phase　reaction　method.　By　introducing　the　high-resistance　phase　Al2O3,　a　three-dimensional　conductive　composite　of　ZnAl2O4　and　ZnO　was　formed.　This　composite　exhibited　excellent　linear　negative　temperature　coefficient　resistance–temperature　characteristics　spanning　from　343　to　513 K.　The　highest　linearity　(R2　=　0.9984)　was　observed　when　x　=　0.05.　©　The　Author(s),　under　exclusive　licence　to　Springer　Science+Business　Media,　LLC,　part　of　Springer　Nature　2024.