Rapeseed(Brassica napus L.) is the main source of edible vegetable oil in China, and increasing seed oil content is the most effective way to increase the supply of rapeseed oil. In this study, 43 genes related to lipid synthesis were selected by analyzing the seed transcriptome data of 4 rapeseed inbred lines 25, 35, and 45 days after pollination. Among them, 33 genes were continuously up-expressed and 10 genes were continuously down-expressed from 25 to 45 days of seed development. The main genes included BnLEC1, BnABI5, Bn OLEO4, and BnOBAP1a. At the same time, combined with the resequencing data of 50semi-winter Brassica napus, 3 SNPs and 9 SNPs significantly related to oil content were detected to BnOBAP1a-A10 and BnABI5-A05, respectively, and the oil content of BnOBAP1A-A10__Hap1 was significantly higher than Hap2. The oil content of BnABI5-A05__Hap1 was significantly higher than Hap3. In addition, WGCNA was used to construct gene networks, and we found that BnOBAP1a and BnABI5 were indirectly connected