<p>Planetary roller screw (PRS) is widely used in various fields with the advantages of strong load capacity, high transmission precision, and good stability in comparison with traditional roller screw. The roller of PRS is prone to bending deformation during the surface hardening process and heat treatment process, which reduces the transmission smoothness and accuracy and shortens the service life. Traditional grinding methods can correct the geometric error brought by the strengthening treatment, but grinding has the disadvantages of low efficiency, high cost, and loss of hardening layer. Moreover, there are few studies on the straightening process of parts with tooth features. In this paper, a new radial feed-in rotary straightening method is proposed to improve the accuracy and the consistency of roller, and experimental study and finite element simulation of the roller straightening process are conducted to obtain the optimal process parameters to reduce the tooth deformation of PRS rollers and the runout error of PRS rollers. The lead accuracy and no-load torque of the rollers straightened with the obtained optimal parameters are greatly improved, which proves the feasibility of the new proposed roller straightening process and verifies the reliability of the optimization of process parameters. This paper provides an investigation foundation of the straightening process for the small-diameter parts containing tooth shape features and provides good practical value for the design of straightening rollers with tooth, the selection of process parameters, and the consistency analysis of straightened products, which promotes the industrial application of the straightening process.</p>