Abstract: The internal irradiation caused by tritium is very harmful to human body, so it is very important to evaluate the level of tritium internal irradiation of related workers. The measurement of urine tritium is a common method to evaluate tritium intake and internal radiation dose of radiation workers. In order to meet the requirements of rapid and accurate assessment of tritium intake level of related workers, based on the direct measurement method of original urine, in this paper, the activity concentration of tritium in urine of three tritium related workers was measured by internal standard quenching correction method. And also evaluate the uncertainty of the measurement results, and estimate the lower detection limit of this method. Through the measurement, the activity concentrations of tritium in urine of Li, Hu and Huang workers were 94.9, 554 and 898 Bq/L respectively, and the deviation from the measurement results of oxidative distillation method was within 4%. The results show that this method is simple, fast and accurate, and it can meet the requirements of urine tritium monitoring and rapid and accurate evaluation of internal irradiation dose of tritium workers.