The invention discloses a sample dissolving method for cobalt-based superalloy GH5605. The method comprises the following steps that: sulfuric acid and phosphoric acid are added into a to-be-detectedsample so as to dissolve the sample, so that the cobalt-based superalloy can be dissolved quickly and completely; the content of chromium, nickel, tungsten, iron, manganese and cobalt in the cobalt-based superalloy (GH5605) is directly measured on ICP-AES by means of a matrix matching curve method, and therefore, a method for measuring the chromium, nickel, tungsten, iron, manganese and cobalt inthe cobalt-based superalloy (GH5605) is established. With the sample dissolving method of the invention adopted, the content of the chromium, nickel, tungsten, iron, manganese and cobalt in the cobalt-based superalloy (GH5605) can be accurately and effectively measured. The method has the advantages of accurate analysis result, good experimental data reproducibility and quailed recovery rate data.With the method adopted, the problem of the analysis of the chromium, nickel, tungsten, iron, manganese and cobalt elements in the cobalt-based superalloy (GH5605) is solved.