<?php
wp_nav_menu( 
array(
'theme_location'=>'primary',
'depth' => 0
));
?> 

对应的HTML

<div class="menu-my-primary-menu-container">	
	<ul id="menu-my-primary-menu" class="menu">
		<li id="menu-item-7" class="menu-item menu-item-type-custom menu-item-object-custom current-menu-item current_page_item menu-item-home menu-item-7"><a href="http://127.0.0.1/startbootstrap/" aria-current="page">首页</a></li>
		<li id="menu-item-8" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-8"><a href="http://127.0.0.1/startbootstrap/sample-page/">示例页面</a></li>
	</ul>
</div> 

如果菜单配置了二级菜单

<div class="menu-my-primary-menu-container">
	<ul id="menu-my-primary-menu" class="menu">
		<li id="menu-item-7" class="menu-item menu-item-type-custom menu-item-object-custom current-menu-item current_page_item menu-item-home menu-item-7"><a href="http://127.0.0.1/startbootstrap/" aria-current="page">首页</a></li>
		<li id="menu-item-8" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-has-children menu-item-8"><a href="http://127.0.0.1/startbootstrap/sample-page/">示例页面</a>
			<ul class="sub-menu">
			<li id="menu-item-23" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-23"><a href="http://127.0.0.1/startbootstrap/test-page/">测试页面</a></li>
			</ul>
		</li>
		<li id="menu-item-21" class="menu-item menu-item-type-taxonomy menu-item-object-category menu-item-21"><a href="http://127.0.0.1/startbootstrap/category/uncategorized/">未分类</a></li>
	</ul>
</div>