Spring oilseed rape is a dominant crop in Qinghai，which is colds and resistant to humidity.Exploring its high-yeild cultivation techniques and theories is of great significance to the supply of edible oil and protein in the area.A field experiment was conducted to explore the effect of film mulching and biochar application on dry matter accumulation, nutrients uptake, seed yield of spring oilseed rape and soil aggregate structure during 2019.It was aimed at illuminating the effect and mechanism of film mulching and biochar application on oilseed rape in Qinghai Plateau.Dry matter accumulation of spring oilseed rape had a fast growth rate at flowering and pod-filling stage.The total biomass at initial flowering stage was significantly increased by film mulching and biochar, which were 192% and 102% higher than CK, respectively.Biochar and film mulching significantly improved N and K uptake of aboveground biomass, among which biochar increased by 44% and 34% while film mulching increased by 135% and 133%, respectively, compared with CK.Film mulching significantly improved the partition of N into stem, which was enhanced from 0.12 to 0.15.Biochar and film mulching increased yield by 9% and 34%, respectively.Film mulching and biochar improved oilseed rape yield mainly by increasing the number of pods per plant, especially number of pods per effective branch.The study indicated that film mulching increased the proportion of 0.25~2 mm aggregates, and the proportions of >0.25 mm water-stable macro-aggregates increased with biochar by 14.8%, while the value of mean weight diameter increased by 23.1%，wich is conducive to the formation of soil agglomeration.