A disclosed a method for improving material identification capability of a double-energy radiation system comprises step 1, determining the atomic number and the thickness of a to-be-detected material; step 2, calculating the pulse quantity ratio (or dosage ratio) based on the atomic number and the thickness of the to-be-detected material; and step 3, adjusting the pulse quantity ratio (or dosage ratio) of the double-energy radiation system into the calculated ratio. The invention also discloses a double-energy radiation system. By utilizing the method and the system, the optimum material identification state of the double-energy radiation system can be rapidly obtained, and results of scanning detection under the state show that the material identification capability of the double-energy system is substantially improved.