Edge chipping of wave-transmitting ceramics in milling is prone to be presented, so the type, location of edge chipping has been investigated with different cutting depth experiments. The effect of cutting depth on edge chipping and the mechanism have also been analyzed. Finally, edge chipping control methods have been proposed. The results show that the edge chipping is mainly concentrated at the exit seamed edge and the entrance side edge of the milling tool when the depth is from 0.4mm to 0.8mm. With the increasing of cutting depth in brittle domain machining, the edge chipping is added. One way of controlling edge chipping is to reduce the cutting depth to no more than 0.3mm, another way is to using the tool path planning method of follow periphery, and ensure that the angle between speed direction and the feed direction is not less than 90°.The investigation provides technical support to improve the surface of the wave-transmitting Si₃N₄ ceramics in milling.