Usability design is an important reference standard to judge the quality of product.The automatic tea-brewing machine was used as an example to summarize the usability design method from structure design,human-machine engineering,reverse engineering,etc.The usability design on discharge port,switch button,lid and base of the tea brewing machine was carried out.In order to increase the usability of the automatic tea brewing machine,some measures on prompt,simplifying the operation step,planning functional area and visual visualization were adopted.The method of product usability design provided almost all instruction steps and method for usability design and verification.