The invention discloses a guide device of a thread rolling machine. The guide device comprises a guide rail and a pushing mechanism; the guide rail comprises a first guide section and a second guide section; the pushing mechanism is arranged in the joined place between the first guide section and the second guide section; a first inner side wall and a second inner side wall are arranged on the first guide section and the second guide section; the side, towards the second guide section, of the first inner side wall is connected with a first rotating wall capable of outwards rotating; the side,towards the first guide section, of the second inner side wall is connected with a second rotating wall capable of outwards rotating; and the first rotating wall is joined with the second rotating wall. The guide device further comprises a first elastic return piece and a second elastic return piece; the first elastic return piece is mounted on the first inner side wall or the first rotating wall;and the second elastic return piece is mounted on the second inner side wall or the second rotating wall. When workpieces are descended to convey in the guide rail, the problems of knocking into airof the workpieces or damage of the guide rail due to collision of the workpieces with the first inner side wall are prevented.