The present disclosure relates to the technical field of preparation of syndiotactic 1,2-polybutadiene (s-PB), in particular to a catalytic system and use thereof, and a preparation method of s-PB. In the present disclosure, the catalytic system includes an iron-containing organic compound, an azodicyano compound, an organoaluminum compound, and a free radical scavenger; where an iron element in the iron-containing organic compound, the azodicyano compound, the organoaluminum compound, and the free radical scavenger have a molar ratio of 1:(0.5-10):(5-100):(1-1000); and the free radical scavenger is selected from the group consisting of a sterically hindered phenol, a sterically hindered amine, and a phosphorus-containing antioxidant. The catalytic system can prepare the s-PB with a high activity at a high temperature, and the s-PB has a melting point of 60° C. to 130° C. with an extremely low gel content or even no gelation.