The invention relates to a digital roving testing machine, comprising a feed mechanism, a drafting mechanism, a twisting mechanism, a winding mechanism, a forming mechanism and a digital control system. The forming mechanism comprises a rail lifting mechanism, and is characterized in that the forming mechanism adopts a ball screw slide block lifting mechanism, wherein the ball screw slide block lifting mechanism comprises two ball screws which are vertically symmetrically arranged inside a vehicle head and inside a vehicle tail; front and back of each ball screw are respectively vertically and symmetrically provided with a linear guide rail; lifting slide blocks are assembled on a pair of nuts on each ball screw; the two lifting slide blocks are respectively fixedly connected with the two ends of a lower rail; symmetric connecting arms in the front and the back of each lifting slide block are respectively in sliding connection with the front linear guide rail and the back linear guide rail; one forming motor is in mechanical connection with one end of a screw connection shaft by a forming speed reducer and one shaft coupling; the other end of the screw connection shaft is in mechanical connection with the other forming speed reducer by the other shaft coupling; and the forming motor is an independent servo motor, and is driven and controlled by a forming AC servodrive controller of the digital control system.