You can use WordPress’s custom menu function to implement the drop-down menu; the detailed method is as follows:

1. Add the following code to functions.php to make the theme support the custom menu function. As shown in the code:

2. Add a top menu. As shown in the code in the picture:

3. Put the wp_nav_menu() function into a custom function. As shown in the code in the picture:

4. In the appropriate header.php The position calls our custom function.

5. A custom menu is already supported. Next, jQuery is used to realize the animation effect of the menu. The code is shown in the figure below:

6. In this way, the drop-down menu is completed.