In recent years, quite a few breakdowns of cable joints occurred due to closing of circuit breakers after tripping in the 110 kV cable line. To study the reason why cable joints break down, the transient behavior of cable joint under the condition of breakers opening and closing is studied in this paper. Firstly, a RLC equivalent model of cable joint is given and an 110 kV cable line is simulated by PSCAD, then the effect of closing or opening angle, the length of line and the number of joints on overvoltage of joint are analyzed, to find out the joints with the most serious over-voltage. Additionally, the internal electric field distribution of joint with serious overvoltage is simulated by ANSYS. The results show that the overvoltages of the joint at 60%~75% of B phase and C phase line are more serious than other joints; meanwhile there are more than 40 kHz high frequency components of overvoltage in joint shielding. What’s more, the maximum electric field strength on the interface between silicone rubber and cross-linked polyethylene and the maximum field strength at the end of the high-voltage shielding tube are doubled than when there is no overvoltage, and the maximum interfacial strength exceeds the security threshold. In the process of breakers closing after tripping, the joints at 60%~75% of the line repeatedly suffer overvoltage, in which the increase of electric field strength at the end of high-voltage shielding tube and the high frequency oscillation in joint shielding both easily cause breakdown of joints.