The present invention discloses a line gear mechanism for rotation-movement conversion, comprising a driving line gear (1) and a driven line gear (2). A stagger angle between an axis of the driving line gear and an axis of the driven line gear is any value from 0° to 180°. By a point contact meshing between a driving contact curve of a driving line tooth on the driving line gear (1) and a driven contact curve of a driven line tooth on the driven line gear (2), and by utilizing rotation of the driving line gear (1), it achieves that the driven line gear (2) rotates while moving smoothly. The line gear mechanism for rotation-movement conversion is simple in structure, easy to design, can achieve small displacement of movement, and is especially suitable for the conversion of small machinery from rotation to linear motion.