External post for stair railing and stair railing with external post

The utility model discloses an external post for a stair railing and a stair railing with the external post. The external post is a hollow sleeve; and at least one slot is concavely formed on the outer surface of the sleeve, and extends downwards from the top of the sleeve. The external post can be sleeved on an internal post matched with the hollow sleeve; and the external post is simple in structure and convenient in use, and can work in with the internal post which is used as a temporary upright post to form a new stair railing, so as to save the construction cost of a corridor and improve the construction efficiency. Besides, the external post is in plug-in connection with a railing panel, so that the stair railing can be assembled more conveniently and mounted more quickly, and the height of the railing panel can be adjusted flexibly. Furthermore, cross rods are in rotational connection with plug-in connection parts, so that the cross rods can adapt to stairways with different slopes and achieve a wider