A horizontal bar device comprises at least three vertically disposed struts, and crossbars connected between the two adjacent struts. A plurality of sleeves are sleeved on an upper part of each of the struts with the sleeves being stacked on top of one another, each end of each of the crossbars is fixedly connected to one of the sleeves, and each of the struts has a blocking surface capable of preventing the sleeves from sliding downward. A positioning structure is disposed between the two adjacent sleeves capable of preventing rotation of the sleeves. An upper end of each of the struts is sleeved with a locking sleeve, and the locking sleeve is pressed against the sleeves through a fastener.