<p>Conventional offset strategies, which first generate offset curves and then apply additional procedures to remove self-intersections, are widely adopted for tool path generation in NC machining. However, this passive approach of handling self-intersections often results in sharp corners and residual uncut regions near the intersection zones. These issues become especially pronounced on dental crown models that feature deep concavities and drastic curvature variations. To address these issues, a proactive self-intersection avoidance tool path generation method is proposed in this paper. Motivated by the geometric property that “outward offsets of convex curves inherently prevent self-intersections”, a simple yet effective inside-out convex offset strategy is first proposed, to preserve the self-intersection-free nature of convex curves on complex dental crown models and generate uniform tool paths across the surface of the dental crown model. To implement this strategy robustly, a convexity-preserving curve offset approach is presented to ensure the self-intersection-free propagation. Moreover, to facilitate the applicability of the proposed method to 3+2-axis machining scenarios, a reliable intersection point detection and curve trimming approach is further proposed for resolving intra-intersections between offset curves. Experimental validation on complex dental crown model confirms that the method can generate smooth, uniform, and self-intersection-free tool paths, inherently avoiding sharp corners and uncut regions that often result from conventional offset strategies, thereby achieving improved surface quality. This method further provides a systematic solution for proactive self-intersection avoidance offsetting on intricate freeform surfaces.</p>