The invention relates to a molded case circuit breaker device with a thermal overload alarm but non-release function. The molded case circuit breaker device is characterized by comprising a base, a circuit board fixing base, a circuit board, bimetallic strips, pull rods, brackets and cam screws, wherein the circuit board fixing base is arranged on the base; the circuit board is fixedly arranged on the circuit board fixing base; the circuit board is provided with microswitches which are connected with an external alarm device through leads; the bimetallic strips are vertically arranged on the base; and one end of each bimetallic strip is in contact with a heating element on the base, and the other end of each bimetallic strip is fixedly connected with the pull rods, the brackets and the cam screws in sequence, so that the bimetallic strips drive the cam screws to trigger the microswitches when the bimetallic strips are bent due to thermal overload, and a triggering signal is transmitted to the external alarm device for alarming. Compared with the prior art, the molded case circuit breaker device has the advantages that the pull rods and brackets are driven after the bimetallic strips are bent by heating, so that the cam screws drive the microswitches to trigger the signal, and the signal is output to the external alarm device to realize thermal overload alarming, large stroke adjusting space and the like.