The invention provides a large-current burn-in device of a vacuum arc extinguish chamber, relating to a processing method of an electric switch. The device comprises a rack, a lower electrode mechanism on the rack and an upper electrode mechanism on the lower electrode mechanism, wherein the upper electrode mechanism comprises a contact compression bar of a static cover plate of the vacuum arc extinguish chamber; the contact compression bar is connected with a vertical slide rail and provided with a contact compression bar driving device; and the lower electrode mechanism comprises a fixed bar of a conducting bar of the vacuum arc extinguish chamber and the fixed bar is connected with a fixed bar driving device. In the large-current burn-in device, a capacitor discharges to generate transient currents which are used for carrying out burn-in on the vacuum arc extinguish chamber in a low-current arcing state and simulating actual inrush currents on the vacuum arc extinguish chamber in a closed state, thus the burn-in diathermanous depth of a contact of the vacuum arc extinguish chamber is higher, and the reignition rate and NSDD (non-sustained disruptive discharge) phenomenon of the vacuum arc extinguish chamber can be reduced effectively; and the large-current burn-in device is simple in the structure and lower in the cost.