The utility model relates to an improved ion chromatograph and belongs to the ion chromatograph. A first six-way sample inlet change-over valve is respectively connected with a first quantification ring, a first sample container, a first leacheate pump and a first protection column, the first leacheate pump is sequentially connected with a first leacheate generator and a first hyperpure water tank, the first protection column is sequentially connected with a first separation column, a first suppressor, an electrical conductivity detector and a data processing system, a second six-way sample inlet change-over valve is respectively connected with a second quantification ring, a second sample container, a second leacheate pump and a second protection column, the second leacheate pump is connected with a second leacheate generator, and the second protection column is sequentially connected with a second separation column, a visible ultraviolet detector and the data processing system. The improved ion chromatograph has the advantages of being novel in structure and capable of enabling an instrument to simultaneously measure negative ions and transition metal ions of different samples or a same sample through improvement, achieving a purpose of two ion chromatographs, saving fund and improving efficiency.