The effect of F-T diesel adding 10% volume of methanol, ethanol and butanol fuel on the combustion and emission characteristics was investigated. Results show that : Compared to the base line diesel fuel, the ignition time advanced and the combustion heat release center is postponed. The first peak combustion heat release rate decreased, phase advance. Premixed combustion heat reduced, which is beneficial to realize low temperature combustion. The other peak value increased and the diffusion combustion in proportion increased. Compared to the original machine level, the dynamic performance of the mixed fuel decreased, little change in economic performance. Under 2000 r/min of external characteristic, M10, E10, N10 NOX emissions were reduced by 23.19%, 19.77%, 18.67% respectively，carbon smoke emissions were reduced by an average 80.40%, 67.20%, 71.47% respectively. Diesel engine fuelled with CTL-Alcohol blends can simultaneously decrease both soot and NOX emissions, and the same volume of methanol fuel have a good effect on diesel engine emissions optimization.