Abstract: Abstract: Energy-saving and less emission have become the stringent requirement to improve the performance of modern diesel engines. The general rail technology at high pressure is a key field to realize the low emission and low fuel consumption of diesel engines, because the multiple injections can be realized easily at each cycle of each cylinder in common rail diesel engines. The rise rate of combustion and pressure in the diesel engine can also be controlled more flexibly and accurately by the multiple injections at high pressure. However, there are great negative influence on the engine performance and electronic control unit, when the multiple injections interferes or overlaps with each other. This present study was focused on the influence of the pre-injection overlapped with the main injection in varying degrees on the engine performances, injector and controller. An experiment was carried out at three working conditions with different loads. The experimental results showed that the peak current of the injector reached about 39 A, about twice of the normal value of the needed injector, where this injector was most likely to be damaged. The injector was in a continuous open state when the pilot injection overlaps the main injection, where the overlapping percentage was 0. In this case, two injections were superimposed as one injection, and the pre-injection effect disappeared, which can prolong the ignition delay. Compared with overlapping percentage -50%, the increase of ignition delay angle of 0 overlap at three working points was 4.1, 4.8 and 5.2 °CA, and the increase rate was 86.7%, 115% and 99%, respectively. In the ignition delay, the combustion pressure and the instantaneous heat release rate increased, resulting the increase of the combustion temperature and the combustion noise in the cylinder. The emission performance of the diesel engine can also affected. In order to prevent the interference or overlap of multiple injections, an inhibition strategy based on the evaluation of the injection pulse width was proposed to coordinate the injection taking place at a reasonable location. Whether pre-injection can interfere or overlap with the main injection was investigate under this strategy based on the injection pulse width. When the result was interference or overlap, a new injection angle of pre-injection was calculated by the inhibition strategy based on the current pre-injection, the maximum pre-injection advance angle, the current main injection advance angle and the minimum injection interval. In this way, the pre-injection was coordinated within a reasonable range and cannot interfere with the main injection if the pre-injection occurred at the calculated injection angle. This strategy to inhibit the inference of multiple injection can contribute to the light vehicle emission for the better design of the modern diesel engines.