A low-calcium carbon-fixing cement clinker mainly composed of β-C₂S was successfully manufactured using from municipal solid waste incineration fly ash and bottom ash. The results show that the clinker can be sintered at 1 150-1 250 ℃， and the actual n（Ca）/n（Si） value required is higher than the theoretical design value， that is， n（Ca）/n（Si）>2.6. Otherwise， it is easy to over sinter and prone to produce calcium alumina feldspar， which is not conducive to the clinker strength development. n（Ca）/n（Si） value has a significant influence on the early compressive strength and carbonation degree of cement， and the compressive strength decreases with the increase of n（Ca）/n（Si） value. The produced cement with n（Ca）/n（Si）=2.8-3.2 upon 2 days of carbonation can attain a compressive strength of 50 MPa， or even up to 72 MPa. However， when the n（Ca）/n（Si） value increases to 3.3-3.7， the compressive strength drops to 25-30 MPa with CaCO₃ content of about 12.00%. Future research is needed to elucidate the role of hydration and carbonation mechanism of various minerals in contributing the strength development.