The invention discloses a joint cutting and filling integrated machine for road building. The joint cutting and filling integrated machine comprises a cutting blade, a water tank, a bearing base plate and a mixing burdening tank. Four corners at the bottom end of the bearing base plate are each provided with a roller, the water tank is installed at one end of the top of the bearing base plate, and the mixing burdening tank is installed at the other end of the top of the bearing base plate; a pressurization device is installed between the mixing burdening tank and the water tank, a connecting frame is installed on the bearing base plate of the side, away from the pressurization device, of the water tank, and a fixing block is installed at the top end of the side, away from the water tank, of the connecting frame; and a booster pump is installed on the bearing base plate of the side, away from the pressurization device, of the mixing burdening tank, and a jetting gun is installed on the side, away from the mixing burdening tank, of the booster pump. The joint cutting and filling integrated machine for road building can achieve the road joint cutting and filling integrated automatic operating function and has the advantages that joint cutting and filling do not need labor, joint cutting precision is high, joint cutting quality is high, road quality is good, and working efficiency is high.