A calculation method of diesel engine cylinder linerpiston ring radial wear was put forward.Taking the marine diesel engine as an example,the combustion pressure curve of diesel engine was simulated under the condition that the injection timings is too large or too small,the wear of cylinder linerpiston ring of diesel engine under different injection timings was calculated.The results show that when the injection timings is too small,the explosion pressure of diesel engine will decrease to cause the incomplete combustion of fuel,the radial wear of cylinder liner near bottom dead centre is higher than that under normal combustion,while the variation trend of the maximum wear is basically the same.When the injection timings is too large,the fuel atomization is decreased or disappeared when the fuel pressure reaches the ignition,resulting in a long time of fuel combustion and a high peak combustion pressure.There will be obvious adhesion wear around the cylinder ignition,the lubricating oil film of cylinder liner near bottom dead centre breaks down to result in the boundary lubrication and the sudden increase of maximum radial wear.