The invention discloses a portable railway wheel tread parameter detection instrument. The portable railway wheel tread parameter detection instrument consists of a base, a cover, a flange tread measuring mechanism, a rim thickness measuring device, a positioning device, a control device, a touch screen and a USB (Universal Serial Bus) interface, wherein the flange tread measuring mechanism comprises a laser sensor and a horizontal moving mechanism; the rim thickness measuring device comprises a positioning mechanism, a measuring head, an electronic ruler and a manual vertical moving guide rail pair; the flange tread measuring mechanism, the rim thickness measuring device and the positioning device are fixedly arranged on the base. The portable railway wheel tread parameter detection instrument is used for detecting the parameters of a railway wheel such as flange thickness, flange height, tread abrasion, rim thickness, rim width, vertical flange abrasion, QR value and tread scratch depth. Laser measurement and the touch screen are adopted, thereby achieving the characteristics of storability of measured data, high accuracy, light weight, convenience in operating and carrying and storability of output data. The portable railway wheel tread parameter detection instrument is suitable for detecting tread parameters under the condition of not lowering down the wheel in plants, workshops, train examination, repair track maintenance, motor car stations, urban subways and the like.