The BJ-4210 wire was prepared by adjusting the chemical composition and adding micron in-situ TiB₂ particles to solve the problems of high crack sensitivity and softening of welding joint during welding of 2195 aluminum-lithium alloy. In this paper， the crack sensitivity， mechanical properties and microstructure of joint were investigated. The results show that the TiB₂ particles， as the nucleation point， can reduce the size of weld grain and changes the morphology of the grain， which can effectively reduce crack sensitivity of the joint and improve its mechanical properties. The tensile strength of joint is 370 MPa， while the elongation of joint is 3.1%. The research of BJ-4210 wire provids technical support for the engineering application of 2195 aluminum-lithium alloy.