This study provides an in-depth investigation of customer management in the construction decoration industry, focusing on Shanghai A Construction Engineering Co., Ltd. By analyzing the company's operational data, the study emphasizes different ownership types of clients and examines factors influencing the profitability of high-quality client projects. The findings reveal that foreign-funded enterprise clients exhibit significant advantages in project quantity, profitability, and per capita output value within Shanghai A Construction Engineering Co., Ltd. While private and state-owned enterprises also have a certain number of projects, foreign-funded enterprises account for over 70% of the total projects. Moreover, the project profitability of foreign-funded enterprises is notably higher than that of the other two types. However, there is no significant difference in per capita output value among the three types of enterprises. Further regression analysis demonstrates that unique technologies and client-specific attributes have a significant positive impact on project profitability. This implies that enterprises with unique technologies and a deep understanding of client needs can achieve higher project profitability. Additionally, bidding quantities and contract amounts have a positive effect on per capita output value, indicating that participating in more bidding activities and securing high-value contracts can enhance project productivity. In conclusion, the research findings shed light on key aspects of customer management for small and medium-sized construction decoration enterprises. Foreign-funded enterprises possess advantages in project quantity, profitability, and per capita output value. Unique technologies and client-specific attributes have a positive influence on project profitability, while bidding quantities and contract amounts contribute to increased per capita output value. These research results provide valuable insights and guidance for small and medium-sized construction decoration enterprises to comprehend the importance of customer management and develop strategies to enhance profitability and performance. However, the specific implementation strategies need to be adjusted and optimized based on each company's unique circumstances to achieve the best outcomes.