The invention provides a press-fitting tool and a press-fitting process for a steering knuckle rolling needle bearing. The press-fitting tool comprises a power part and a press-fitting part which are fixedly connected, wherein the power part comprises an oil cylinder and a connecting plate; one end of the connecting plate is connected with a steering knuckle, and the other end of the connecting plate is connected with the oil cylinder; the press-fitting part comprises a guide rod, guide sleeves and a baffle block; the guide sleeves are separately arranged at the left end and the right end of the guide rod; the baffle block is arranged between the two guide sleeves; and a telescopic pole of the oil cylinder penetrates through the connecting plate and is detachably connected with the guide rod. According to the structural feature that two main pin shaft holes of the steering knuckle are coaxial, a rolling needle bearing is positioned and is pressed through the guide rod and the two guide sleeves, pushing-pulling force generated by the oil cylinder drives the guide rod to advance and retract, so that the baffle block is driven to separately press the rolling needle bearing into the main pin shaft holes, and therefore, the oil cylinder can act once to complete press-fitting work of two rolling needle bearings, positioning is reliable and assembly quality is high; and moreover, press-fitting operation can be performed on a roller path frame, so that operation is simple and convenient.