By adjusting the 6 injection parameters ( pfin

Tfin

Tint

Qpre

Tinta

Qafter)

the multi-factor and multi-objective performance optimization of the biodiesel engine was researched on a high pressure common-rail diesel engine fueled with 20% biodiesel and 80% diesel. By using hybrid DoE

a multi-factor optimization plan of 9 different operating points was designed and the bed test was carried out to collect the engine performance and emission data. According to the test results

the mathematical model of the performance indexes of the engine was fitted by means of the hybrid RBF algorithm

and the optimization equation was designed. Then the global multi-objective optimal solution was solved by the combinational optimization algorithm with the goal of minimum BSFC and minimum NOx emission. This method can make up for the limitation of the traditional optimization method using single factor one by one. After the optimization

the average BSFC of the selected 9 operating points can be reduced by 2.71%

while the average NOx emission is reduced by 24.59%.