Swedish companies' investments abroad, including in authoritarian states, are an important component of Sweden's export-driven economy. Swedish business operations in China involve various trade-offs, including opportunities for innovation but also risks of technology transfer. This study introduces a method for mapping Swedish companies' business activities in China and their links to critical technology areas in the EU and China. The method is validated and improved through an empirical study based on open-source data covering 167 Swedish companies operating in China. Slightly more than half are assessed not to have any production activities in China but instead focus solely on services and trade. Common industries include consumer goods and services, industrial products and machinery, business services, information and communication technology, and the metalworking and automotive industries. Approximately half of the studied companies have apparent links to the EU's and/or China's critical technology areas, while the rest have peripheral or no connections. The study includes several companies in industries that, prima facie, appear irrelevant yet are engaged in critical technologies; these examples underpin the study's emphasis on an unprejudiced, bottom-up mapping process for analysing companies in a critical-technology context. Future studies could further develop the applied method's reliability and granularity.