This disclosure relates generally to medical devices, particularly to drawer-type paper tray structures for loading paper into electrocardiograph machines. A paper tray structure provided comprises a paper tray and a door component. The door component comprises a door located in front of the paper tray. The door component is connected to the paper tray movably and is configured to move repeatedly between a first position and a second position relative to the paper tray; the paper tray comprises a first restriction surface and a second restriction surface corresponding to the first and second positions respectively.