A method of controlling a comb-cutter lathe in which one face of a tool rest (TBS) is provided with two or more juxtaposed tools (TL1, TL2) for subjecting a workpiece (WK) to machining by using: (1) predetermined tools in succession, (2) part dimensions, (3) a tool selection sequence, (4) a machining start location for each tool, and (5) mounting dimension information measured from a reference point on the tool rest to a distal end of each tool. Machining is sequentially performed based on this information by predetermined tools at machining locations (P.sub.5 -P.sub.4 -P.sub.3 -P.sub.2 -P.sub.1 ; P.sub.6 -P.sub.7 -P.sub.8 -P.sub.9 -P.sub.10) assigned to the tools, and after machining is completed by a first tool (TL1), the tool rest (TBS) is moved to position the next tool (TL2) at a machining location and machining is performed by that tool. The method includes moving the tool rest along a Z axis to a point P.sub.r at which none of the tools (TL1, TL2) will contact the workpiece (WK) when the tool rest (TBS) is moved in a direction (X-axis direction) at right angles to the longitudinal direction (Z-axis direction) of the workpiece, and thereafter moving the tool rest along the X axis to a point P.sub.t at which an X-axis position of a selected tool coincides with an X-axis coordinate value of a position at which machining is to be started by the selected tool, and thenforth performing machining using the selected tool.