Based on the international code, this paper carries out the fine soil investigation work for Hong Kong-Zhuhai-Macau bridge island-tunnel projec to get the soil characteristics as accurately as possible due to the excellent design requirements. According to the successful experience of the fine soil investigation work of the project, the paper discusses the management for the highly qualified personnel staff, process control and full range of coordinating the fine soil investigation mode to satisfy the requirements of the schedule and quality for the fine soil investigation, which provides reference for similar projects.