The invention discloses a method for preparing 2, 3, 5, 6-quadri-aminopyridine hydrochloride which relates to a preparation method of the aminopyridine hydrochloride. The invention solves the shortages of the existing method that the preparation of the 2, 3, 5, 6-quadri-aminopyridine hydrochloride is strict in reaction conditions, high in cost, low in purity;, low in yield, and the 2, 3, 5, 6-quadri-aminopyridine hydrochloride is very easy to be fail in oxidation and is uneasy to preserve. The preparation method of the invention has the following steps: 1. 2, 6-diamino-3, 5-diaminopyridine, water, concentrated phosphoric acid and a catalyst are added into a reactor sequentially; then the reaction carries out in the hydrogen hemisphere with the temperature of 35 DEG C to 75 DEG C and the pressure of 0.8 to 3.0 MPa; 2. filtering is carried out at the protection of nitrogen; 3. the filtrate which is poured into the mixture solution of concentrated hydrochloric acid and tetrahydrofuran is static at a room temperature; 4. the filtering is carried out under the protection of the nitrogen and a solid formation is dried in vaccum. The method for preparing 2, 3, 5, 6-quadri-aminopyridine hydrochloride has the advantages that: the product is high in purity and yield without side products; the products are uneasy to oxide and easy to store; the catalyst can be used repeatedly; the production cost is low; the technique is simple; and the method is suitable for commercial process.