The invention relates to a method for measuring content of total nitrogen in a urea-ammonium nitrate solution containing 27%-33% of nitrogen. According to the method, concentrated sulfuric acid is added to the urea-ammonium nitrate solution, amide nitrogen is converted into ammonium nitrogen, a nitrogen-fixation alloy is added, nitrogen in various forms is sequentially converted into ammonium nitrogen, sodium hydroxide is added, ammonium nitrogen is converted into ammonia to be distilled, ammonia is absorbed with a boric acid solution, a standard sulfuric acid titration solution is used for direct titration, and the content of total nitrogen is calculated. Compared with an existing method of back titration after distillation and a method of direct titration after distillation, the method has the advantages that the steps are reduced, the operation is simpler, more convenient and more fast, the analysis procedure is greatly shortened, coexisting complicated matrix components, manual operation and other factors cause little influence on measurement, the interference capability of the method is enhanced, the accuracy and the precision of a result are improved, and the analysis and checking cost is very low.