In order to solve the problem of high-precision installation of trapezoidal hollow components in deepwater channel regulation project,we study the development and application of measurement and positioning technology for the underwater installation of components to provide accurate orientation data for the underwater installation and meet the requirements of construction accuracy.Referring to the external structural dimensions of trapezoid hollow components and using the GPS and inclinometer equipment installed on the measuring frame to collect and calculate relevant positioning data of the components,we accomplish the fist-time adjustment of the components according to the measurement results.Then,by analyzing the component images acquired underwater,we calculate the gap width between components and adjust the components accurately for the second time according to the analysis results.The practical application shows that the plane and elevation measurement error of the system is not more than ±3 cm,and the measurement accuracy is high,which can meet the accuracy requirements of underwater installation.