First of all, we need to know whether there is any infringement fact. In the case of appearance patent infringement, a key aspect of defense is to prove that the accused product is different from the plaintiff's patent design. What you need to point out is that the appearance of this product is obviously different from the patented design. To this end, we can seek professional designers to identify products and provide professional analysis or evidence to prove product differences.

Secondly, we can consider demonstrating whether the design patent meets the registrable standard. In some cases, the plaintiff's patent may be defective or not meet the requirements of the patent law. You can cite relevant laws and cases, as well as the opinions of professional patent lawyers to support your defense.

In addition, we can consider discussing issues related to the scope of patent rights. For example, in some cases, the patent may only apply to specific design elements or features, and the accused product may only be similar to the patent in some aspects. You can make analysis and comparison to prove that the accused products are not beyond the patent scope.

Finally, you can seek other defenses, such as invalidation of patent right and duplication with other previously registered designs. Through detailed research and investigation, you can find other evidence and reasons to support your defense.

It should be noted that the specific circumstances of each case are different, and the concrete analysis of specific cases is very important. It is recommended that you cooperate with professional lawyers to formulate your defense strategy to ensure compliance with legal procedures and regulations.