The superconducting tokamak device constrains high-temperature plasma through an extremely high magnetic field to achieve a controllable nuclear fusion reaction. To ensure the safe operation of the superconducting magnets, the quench protection system relies on pyrobreaker for critical backup protection. In this paper, the numerical model of current contacts in the 15 kV pyrobreaker has been established and the analysis is carried out for the contact breaking process. The detonation pressure required for contact separation and the pressure distribution law generated by the explosion are calculated. Furthermore, the accuracy of the numerical simulations is verified through experimental validation, providing a theoretical foundation for the design of pyrobreaker.