A circular stapler facilitate performing end to end anastomosis; further an occasional prompt with sound effect warning timely firing the stapler bolts. A circular stapler includes a bolting machine (1) consists of a shaft (11), an actuator (12), and a stapler (13); a hand-held handle (2); an adjusting knob (3); and an anvil (4), a hollow anvil shaft (41);characterized in that: a conic trocar (5) disposed to a most distal end of said bolting machine (1), a cambered surface of said conic trocar (5) formed with, at least, three relieve-pressure grooves (53) equal distant distributed are extended from an apex (51) to a bottom (52); an audio prompt (6) disposed inside said bolting machine (1), said audio prompt (6) includes a printed circuit board (PCB) (61), a buzzer (62) electrically connected to the PCB (61) controlled by a switch, and a battery (64) supplies power to the PCB (61).