A nut pickup and fastening device for automatic tire mounting includes a nut setting unit that arranges a plurality of nuts to align with the bolt arrangement of the wheel disk of a vehicle body, and a pickup fastener coupled to the tip of a robot arm. The pickup fastener may include a tool frame unit, a plurality of nut runners provided on the tool frame unit corresponding to the set nuts and configured to provide torque for nut fastening, and a plurality of holding sockets coupled to the tip of each nut runner, configured to pick up and hold the nuts from the nut setting unit.