The invention discloses a connecting rod big end hole integral machining device. The connecting rod big end hole integral machining device comprises a boring tool bit and a connecting rod positioningmechanism, and further comprises a bottom plate and a working cylinder used for driving the connecting rod positioning mechanism to move relative to the boring tool bit. The connecting rod positioningmechanism and the working cylinder are both arranged on the bottom plate. The connecting rod positioning mechanism is connected with a piston rod of the working cylinder. The connecting rod positioning mechanism comprises a hydraulic cylinder, a fixed plate and a baffle. The baffle is arranged between the fixed plate and the boring tool bit. The baffle is provided with a receding through hole corresponding to the boring tool bit. The fixed plate is located between the hydraulic cylinder and the baffle. A movable pressing block used for pressing the big end of a connecting rod body and a connecting rod cover onto the baffle is arranged in the position, corresponding to the receding through hole, of the fixed plate. The movable pressing block is arranged corresponding to a piston head of the hydraulic cylinder. The connecting rod big end hole integral machining device can conduct integral one-time machining on a connecting rod big end hole. The product quality is improved. The overall machining efficiency is substantially improved.