This paper proposes a finite-time prescribed performance safe tracking control (FPPSTC) method for robotic systems based on the control barrier function (CBF). To address the position safety constraint problem of robotic systems in Cartesian space, a Cartesian-space finite-time CBF (CFCBF) is constructed, which combines the system kinetic energy with the safety constraints by directly established based on the dynamic characteristics of the task space. By leveraging the kinetic energy of the system, the position safety constraint with a relative degree of 2 is reformulated into an equivalent barrier function condition with a relative degree of 1.} On this basis, to deal with the trajectory tracking and obstacle avoidance problem of robotic system in an obstacle environment, a FPPSTC scheme is designed by integrating the CFCBF and prescribed performance constraints into a quadratic program (QP) optimization framework. Based on Lyapunov stability theory, it is further proved that the designed controller can guarantee the finite-time convergence of the tracking error within the predefined performance boundaries. Simulation results show that the proposed method can ensure safe tracking for the robotic systems while achieving finite-time convergence of trajectory tracking error, thereby improving the control accuracy and dynamic performance of the system.