The invention discloses a medium and low temperature brazed diamond drill bit. The medium and low temperature brazed diamond drill bit comprises a steel pipe; the end surface of the welding end of the steel pipe is provided with drainage openings which are uniformly distributed; the end surface between the drainage openings are provided with groove openings which are uniformly distributed; the centers of all the grooves openings are provided with round ports; the diameter of the outer surface of the welding end of the steel pipe is smaller than the external diameter of the pipe wall, so that an external step is formed; the diameter of the inner surface of the welding end of the steel pipe is larger than the internal diameter of the pipe wall, so that an internal step is formed; and the groove opening depth, the round port depth, the length of the inner surface of the welding end of the steel pipe and the length of the outer surface of the welding end of the steel pipe are all equal and smaller than the drainage opening depth. A manufacturing method comprises the step that diamond is brazed on the end surface, the outer surface and the inner surface of the welding end of the steel pipe and in the groove openings and the round ports at the medium and low temperature of 820 DEG C-880 DEG C. The thickness of brazing materials on the inner surface and the outer surface of the welding end of the steel pipe is consistent with the width of the internal step and the width of the external step. According to the medium and low temperature brazed diamond drill bit and the manufacturing method thereof, hot damage to the diamond can be reduced, the bonding strength of the diamond and a blank body is improved, the height of protrusion is increased, accordingly the service life of the drill bit is prolonged, and the cost is reduced.