Spray forming is an emerging manufacturing process. The automated tool planning for this process is a nontrivial problem, especially for geometry-complicated parts consisting of multiple freeform surfaces. Existing tool planning approaches are not able to deal with this kind of compound surfaces. This paper proposes a tool path planning approach which considers the tool motion performance and the thickness uniformity. There are two steps in this approach. The first step partitions the part surface into flat patches based on its topology and normal directions. The second step determines the tool movement patterns and the sweeping directions for each flat patch. Based on that, optimal tool paths can be calculated. Experimental tests are carried out on automotive body parts and the results validate the proposed approach.