The utility model relates to an upper column structure provided with an I-shaped slot. The structure comprises an upper column mounted on a column bracket, wherein a lower column is movably nested in the upper column; the I-shaped slot is formed in one end, where the lower column is nested, of the upper column; the column bracket is connected to the I-shaped slot of the upper column; and a locking mechanism for extruding the upper column to enable the upper column to lock the lower column nested in the upper column is further arranged on the column bracket. With the adoption of the upper column structure provided with the I-shaped slot, the defects of the conventional 1-shaped slot structure can be overcome, and compared with the conventional cam shaft structure, the upper column structure can more stably lock the upper column and the lower column, is simple in structure and has good practicability.