A novel broadband magic-T based on stripline- slotline transition is proposed in this paper.The magic-T based on stripline-slotline transition has many advantages such as wide bandwidth,easy fabrication,excellent phase and amplitude balance.The working principle of the magic-T is analyzed,and the physical parameters of the magic-T with excellent performance are presented.The magic-T is simulated with a 3D FEM electromagnetic simulation software and the results are presented.The frequency bandwidth is more than 40%,when the simulated VSWR of port of the magic-T is less than 2,and the simulated amplitude imbalance is less than ±0.5dB,and the simulated phase imbalance is less than ±0.2°,and the simulated isolation between the sum port and the difference port is higher than 55dB.