The invention discloses a clothes measuring ruler for costume design, which comprises a ruler body and an auxiliary ruler, the right side of the ruler body penetrates to the right side of the inner cavity of the auxiliary ruler, the top of the ruler body is sequentially provided with screw holes from left to right, the bottom of the ruler body is provided with a sliding groove, and the inner cavity of the sliding groove is slidably connected with a sliding block. The top of the sliding block is fixedly connected with the left side of the bottom of the inner cavity of the auxiliary ruler. Through arrangement of the ruler body, the auxiliary ruler, the screw hole, the sliding groove, the sliding block, a fastening screw pin, a screw sleeve, a screw rod, a first bearing seat, a fixed suction cup, a second bearing seat, a rotating disc, a sliding rail, a pulley, a fixing frame, a fixing seat, a fixing ring and a fixing hole, the advantage of convenient adjustment is achieved, and the problems that an existing clothes measuring ruler for costume design is inconvenient to adjust and inconvenient to adjust are solved. The clothes measuring ruler solves the problems that the use length of the clothes measuring ruler cannot be adjusted, meanwhile, one side of clothes cannot be fixed during measurement, the accuracy of data measured by the clothes measuring ruler is affected, and the practicability of the clothes measuring ruler is reduced.