It is an important measure to control the effective prestress accurately by measuring the friction loss of the anchor port and adjusting the tensile force according to the test results during the tensioning construction of the prestressed steel strand. It is of great significance to measure the frictional loss of anchor port accurately to ensure the accurate application of design tensile force. The common problems affecting the measurement of the friction loss of the anchor port are summarized and analyzed by combining many abnormal cases and experiences in the field measurement of friction loss.