Homogeneous charge induced ignition（ HCII） using gasoline-diesel dual fuel was achieved on a sixcylinder diesel engine in this passage. The influence of diesel mixingthoroughness on HCII was studied specifically through significantly advancing the diesel main injection time. Experiment results show that diesel mixingcan optimize the combustion process of HCII. As diesel main injection time advanced to 40° BTDC,the combustion progress largely resembled homogeneous charge compressed ignition. The maximum pressure rising rate can be controlled at appropriately 0. 59 MPa/（ °） while the effective thermal efficiency was maintained at high level. Thorough diesel mixing can also improve the emission performance of HCII significantly. As diesel main injection time advanced to 40° BTDC,NOxemission reduced to 0. 39 g/（ k W·h） while the emission of Soot was almost zero.