A firing mechanism for a surgical stapler, wherein, the firing mechanism comprises an actuating rod provided with a stopping groove , and the firing mechanism further comprises: a firing handle rotatable relative to a housing of the stapler, wherein a pin post is provided in the firing handle , a pin groove for accommodating the pin post is provided in the firing handle , a reset component is provided in the pin groove , and the reset component is located between a second end of the pin post and an end surface of the pin groove , so that the pin post is movable in a straight line along a direction limited by the pin groove , a first end of the pin post is capable of protruding from a first end of the firing handle and entering the stopping groove , to stop the firing handle from rotating relative to the actuating rod ; a button assembly comprising a pressing rod , wherein a first end of the pressing rod is inserted in the firing handle ; the pressing rod is capable of further entering the firing handle , to press the first end of the pin post to move towards a second end of the firing handle ; wherein, when the firing handle is pressed in an initial state, the firing handle rotates from a second position to a first position, the pin post rotates along with the firing handle , the first end of the pin post moves under the function of the reset component until the first end of the pin post enters the stopping groove , to stop the firing handle from rotating back to the second position; characterized in that , the pin post is provided with a first cooperating portion , and the first cooperating portion has a first inclined surface , a first end of the pressing rod is provided with a second cooperating portion , and the second cooperating portion has a third inclined surface ; when the pressing rod is in its initial position, the third inclined surface fits with the first inclined surface . a firing handle rotatable relative to a housing of the stapler, wherein a pin post is provided in the firing handle , a pin groove for accommodating the pin post is provided in the firing handle , a reset component is provided in the pin groove , and the reset component is located between a second end of the pin post and an end surface of the pin groove , so that the pin post is movable in a straight line along a direction limited by the pin groove , a first end of the pin post is capable of protruding from a first end of the firing handle and entering the stopping groove , to stop the firing handle from rotating relative to the actuating rod ; a button assembly comprising a pressing rod , wherein a first end of the pressing rod is inserted in the firing handle ; the pressing rod is capable of further entering the firing handle , to press the first end of the pin post to move towards a second end of the firing handle ; wherein, when the firing handle is pressed in an initial state, the firing handle rotates from a second position to a first position, the pin post rotates along with the firing handle , the first end of the pin post moves under the function of the reset component until the first end of the pin post enters the stopping groove , to stop the firing handle from rotating back to the second position; characterized in that , the pin post is provided with a first cooperating portion , and the first cooperating portion has a first inclined surface , a first end of the pressing rod is provided with a second cooperating portion , and the second cooperating portion has a third inclined surface ; when the pressing rod is in its initial position, the third inclined surface fits with the first inclined surface . <EOS>