Gasoline partially premixed combustion shows the potential to achieve clean and high efficiency combustion. Injection strategies show significant influence on in-cylinder air flow and in-cylinder concentration distribution before auto-ignition, which can significantly affect the combustion characteristics and emissions. This study explored the effects of various injection strategies, including port fuel injection (PFI), single direct injection (DI), double direct injection (DIP+DIM) and port fuel injection coupled with a direct injection (PFI+DIM) on the combustion characteristics and emissions on a modified single cylinder heavy duty diesel engine fueled with 92# gasoline. The results showed that CA5 and CA50 of DIP+DIM are more sensitive to injection timing than PFI+DIM and single direct injection strategy, partially due to the effects of DIP on mixture stratification and low temperature reaction of gasoline. When the DIM injection timing was set at -59CA ATDC and -29CA ATDC, lower HC and CO emissions and higher combustion efficiency could be achieved with PFI+DIM compared with DIP+DIM due to its more homogeneous mixture and no spray impingement on cylinder wall. With fixed CA50 (2.5CA ATDC) achieved by adjusting DIM timing, PFI+DIM and DIP+DIM (DIP@-150CA BTDC) could obtain more stable combustion.