Cavitation in the diesel nozzle can have a serious impact on the performance of the diesel engine. On the one hand, it promotes the atomisation of the fuel, enabling efficient and sufficient combustion of the fuel inside the engine and reducing the possibility of carbon build-up. On the other hand cavitation can cause cavitation wear inside the nozzle, thus affecting the life and performance of the nozzle. This paper investigates the effect of nozzle structural parameters on cavitation performance through computational fluid dynamics using a VOF model plus a cavitation model. Three dimensionless quantities, the gas-liquid inlet angle ratio, the gas-liquid inlet length ratio, and the gas-liquid inlet diameter ratio, are analysed using the dimensionless quantity method. To provide a theoretical basis for future research into the fuel atomisation characteristics of gas-liquid two-phase fuel nozzles.