The invention discloses a measuring device and a measuring method for measuring the length of cloth in the garment sewing process, comprising a device with a first inflection ruler, a measuring soft ruler, a cutting knife, a positioning lock, a bayonet, and a second inflection Ruler, standing bracket, arc scale is installed above the positioning locking device, the bayonet is installed above the arc scale, the second inflection ruler is installed above the bayonet, and the second inflection The standing support is installed above the ruler, the main body of the device is installed below the standing support, a sliding scale is installed below the main body of the device, a sliding ruler is installed below the sliding scale, and a radian scale moving groove is installed above the sliding ruler , a level is installed below the radian ruler moving slot. The beneficial effect lies in that the data of some special parts of the human body can be accurately measured to ensure that the clothes made fit, the structure is simple, and the clothes are convenient to carry.