The continuous development of e-commerce puts forward higher requirements for the marketing strategy of each enterprise. The study applies the SWOT matrix model to e-commerce precision marketing and builds a big data platform to help e-commerce marketing strategies become more precise and efficient. An example analysis of Company S is conducted to explore the problems of the company’s products in product selection, pricing, marketing channels and promotion, and a targeted optimisation plan is proposed using the SWOT method. The marketing effect of the e-commerce precision marketing optimisation plan is analysed.The original product selection idea of Company S is limited to e-commerce pop-ups.The percentage of sales of high-margin products is much higher than that of low-margin products in the total sales of 2023.The original traffic ports of Company S are only on-site advertisements and natural traffic. After the optimisation of marketing strategy, off-site traffic was added to the traffic port of Company S, and the proportion of off-site traffic in the total traffic reached 57.38%, and the off-site traffic casting of Company S produced good results.The sales of Company S in the first half of 2024 (1994544) were much higher than the sales in the first half of 2023 (1479904.84).