Provided is a vehicle measurement system for an automatic conveyor. The measurement system includes: an information measurement unit, disposed at a position higher than the ready-for-loading vehicle and including two laser radars: a rear radar and a side radar; a voice prompt unit, configured to send a voice prompt; and a control unit; where when the ready-for-loading vehicle is approaching, the rear radar measures a distance between it and the ready-for-loading vehicle in real time as a predetermined parking distance; when a value of the predetermined parking distance is within a predetermined range, the control unit controls the voice prompt unit to send a voice prompt for parking; and after the ready-for-loading vehicle stops, the information measurement unit measures the distance between the ready-for-loading vehicle and the rear radar, carriage size information, and a deviation angle of a parking position of the ready-for-loading vehicle from the predetermined parking area.