The invention relates to protection level adjustable tripping devices for a molded case circuit breaker. The tripping devices comprises tension springs, a sliding adjusting button, a supporting part, adjusting drawing bars, adjusting screws, nuts, sleeves, movable iron cores, magnetic coils, static iron cores, magnet yokes, bases, compression springs, tripping parts and tripping drawing bars. The ends of the tension springs are connected with the adjusting screws, and the other ends are connected with the adjusting drawing bar. The ends of the sliding adjusting buttons are connected with the adjusting drawing bar, and the other ends are snapped at corresponding positions of the supporting part. The movable iron cores are formed by threaded connection of the adjusting screws and the sleeves, the ends of the adjusting screws are connected with the tension springs, and the other ends are in threaded connection with the sleeves. The magnetic coils and the static iron cores are arranged in rectangular cavities formed by magnet yokes and the bases, and the static iron cores are fixed below the movable iron cores. According to the device, the structure is simple, tripping is reliable, the multi-current-level adjustable function is achieved, and the production efficiency and the verification efficiency are greatly improved.