This research aims to analyse the key factors of the gem and jewellery business affecting Thailand's export performance, and to examine the relationship between the business model, marketing environment, and the export performance of the gem and jewellery industry in Thailand during the COVID-19 pandemic. Quantitative research based on 400 opinions from Thailand's gems and jewellery business owners has been applied in this study. 369 questionnaires were returned, accounting for 92.4%. Data analysis includes descriptive statistics, structural equation modelling, and path analysis used to test hypotheses. The research results revealed that the business model and marketing environment positively influence a firm's export performance. Only customer segments, channels, value propositions, and creating value for customers had a statistically significant influence on the export performance. To improve its marketing environment, the business should focus on increasing variety and suitable prices, changing promotion to online, trade exhibitions, and creating more variety of products, modern style, and quality product guarantee.