The invention discloses a cable support with automatic umbrella-shaped telescopic legs. The cable support comprises a supporting rod and a thick-walled structure which is arranged in the vertical direction and is provided with a cavity, and further comprises an automatic umbrella-shaped telescopic leg mechanism on the bottom of the supporting rod. The automatic umbrella-shaped telescopic leg mechanism comprises a sliding sleeve and a fixed sleeve which sleeve the bottom of the supporting rod from top to bottom in sequence, four engaging lugs are respectively welded into four quadrants at the same height on the side walls of the sliding sleeve and the fixed sleeve, the engaging lugs are parallel to each other and face the outer side, a supporting leg penetrates through the portion between two adjacent engaging lugs on the sliding sleeve through a bolt, and two connection rods penetrate through the portion between two adjacent engaging lugs on the fixed sleeve through bolts. According tothe cable support, the supporting legs can automatically retract under the gravity effect, folding of the supporting legs is achieved through movement of the sliding sleeve, the cable support is convenient to carry, and meanwhile a stable triangular supporting structure is formed between the supporting legs and the connection rods after the supporting legs are opened, and the cable support is firm and reliable.