The invention provides an automatic guardrail component punching machine. The automatic guardrail component punching machine comprises a control console, a stepping motor, a guardrail punching die structure, a guardrail component clamping device and a carriage traveling mechanism. The carriage traveling mechanism comprises a square frame, two supporting rods are erected on the square frame abreast, a supporting plate is arranged below the square frame, and a rack, a linear slide rail and a stepping motor transmission chain are arranged on the supporting plate sequentially from outside to inside. The stepping motor is disposed on the supporting plate of the square frame, a speed-changing gearbox is arranged on a rotating shaft of the stepping motor, and the control console controls the stepping motor to work. The guardrail component clamping device is arranged on the two abreast supporting rods, a supporting table is arranged at the front end of the square frame, and the guardrail punching die structure is arranged on the supporting table. The automatic guardrail component punching machine is capable of clamping guardrail components to be machined and is high in punching efficiency and punching precision and higher in operation efficiency.