The invention discloses acontrast agent auxiliary injector for intervention department and an auxiliary supporting assembly thereof, and relates to the technical field of medical instruments, which comprises an injection mechanism, and an auxiliary injector and an auxiliary supporting assembly which are used for moving the injection mechanism; the injection mechanism comprises an injection pipe, an injection head arranged at one end of the injection pipe, a piston installed in the injection pipe in a matched mode and a push rod fixedly connected to one end of the piston. The auxiliary injector and the auxiliary supporting assembly provided by the invention are reasonable in structure, scale marks are arranged on the injection pipe, the injection pipe is a transparent pipe, the injection amount of a contrast agent is convenient to observe, the contrast agent is convenient to inject by arranging the push rod pushing part, operation is convenient, labor is saved, pushing of the push rod to move is stopped by arranging a push rod thrust unit, the elastic force of a limiting spring, a thrust piston and a thrust rod, so that unnecessary pain of the patient caused by excessive liquid in the biliary tract due to the fact that the blood vessel of the patient is blocked and the contrast agent is injected into the body of the patient through mechanical thrust is avoided.