In the era of new technology, career assessment services are faced with the challenge of diversified and personalized needs of customers, which requires a new theoretical perspective to respond [1]. Based on DeepSeek artificial intelligence technology driven career assessment as the background, this paper discusses the construction method and significance of career assessment enterprise customer mental model. Starting from the theoretical basis of mental model, this paper analyzes the cognitive, behavioral and emotional components of customer mental model and its role in career assessment service, and expounds the theoretical contribution of DeepSeek and other artificial intelligence technologies to the construction of mental model. Research shows that big data analysis based on artificial intelligence can describe the implicit psychological model of customers, enrich the theoretical tools for career decision support, and help realize the accuracy and individuation of career assessment services [2]. This study provides new ideas for the transformation of career assessment industry, reveals the theoretical significance of integrating customer mental model into career planning service to improve decision support effect, and looks forward to the future development direction of career assessment service driven by artificial intelligence.