Objective To explore the feasibility of using constant temperature drying oven instead of constant temperature digester in the determination of urinary iodine by arsenic cerium catalytic spectrophotometry. Methods Using constant temperature drying oven instead of constant temperature digestion apparatus to digest urine samples, the reagents and other operation steps were the same as the standard method.The detection limit, linear range of standard curve, precision, recovery of standard addition and determination results of reference materials were analyzed.The detection results of 30 urine samples were compared between the two methods. Results The range of urine iodine concentration was 0-300μg/L, the correlation coefficient∣r∣=0.9995-1.0000, the lowest detection value was 1.9 μg/L (sampling volume was 0.25 ml).The range of urine iodine concentration was 300-1 200μg/L,the correlation coefficient∣r∣was 0.9992-0.9999, the recovery rate was 97.3% - 100%, and the precision (RSD) was 1.09%-1.43%.There was no significant difference between the two methods (t = 1.170, P> 0.05). Conclusion The temperature uniformity is good, and the precision and accuracy of the method can meet the requirements.