The navigation bar at the bottom of the Taobao mobile app can be set by following the steps below: First, determine the style and layout of the navigation bar, including the number and position of navigation items. Then, use HTML and CSS code to create the structure and style of the navigation bar. You can use flexbox or grid layout to achieve adaptive and responsive design of the navigation bar. Next, add corresponding links or event handlers to each navigation item so that users can navigate to the corresponding page or perform corresponding operations when they click. Finally, add the navigation bar to the page of the Taobao mobile app, and test and adjust it to ensure that the function and style of the navigation bar meet expectations.