In order to reduce the header splashing losses of rape combine harvester, an online collection method with its device was proposed based on the transverse positive pressure airflow for row depending rape harvester. The collection process was analyzed and optimized by theoretical calculation, virtual simulation and bench test. The falling height of rapeseeds and airflow velocity were selected as main studying factors by theoretical analysis firstly. Fluent-EDEM coupling simulation tests were carried out to analyze how these two selected factors affected the collection rate without rape stalks, and two counter measures, including addition of auxiliary collection screen and gridding the collecting grooves were put forward. Finally, the bench tests were conducted to verify whether the measures were effective. The results showed that rapeseeds collection rate was increased with the decrease of falling height, and gone down with the descending of airflow velocity. The falling height, airflow velocity and interaction between them influenced rapeseeds collection rate significantly. The location of auxiliary collection screen and its interactions between other factors were not significant. The best test combination was A3B3C3. It was under the condition with auxiliary collection screen installed on the fourth collection grove, falling height set as 200mm and frequency of the converter was 50Hz. With gridded collecting grooves and auxiliary collection screen, the best collection rate was 70.34%, while without them the collection rate was sharply decreased to 48.02%, which indicated that the two improving measures were effective.