应该是样式问题！你参考一下我下边这个成功例子吧！
菜单项状态
.dropdown-submenu {
position: relative;
}
.dropdown-submenu > .dropdown-menu {
top: 0;
left: 100%;
margin-top: -6px;
margin-left: -1px;
-webkit-border-radius: 0 6px 6px 6px;
-moz-border-radius: 0 6px 6px;
border-radius: 0 6px 6px 6px;
}
.dropdown-submenu:hover > .dropdown-menu {
display: block;
}
.dropdown-submenu > a:after {
display: block;
content: " ";
float: right;
width: 0;
height: 0;
border-color: transparent;
border-style: solid;
border-width: 5px 0 5px 5px;
border-left-color: #ccc;
margin-top: 5px;
margin-right: -10px;
}
.dropdown-submenu:hover > a:after {
border-left-color: #fff;
}
.dropdown-submenu.pull-left {
float: none;
}
.dropdown-submenu.pull-left > .dropdown-menu {
left: -100%;
margin-left: 10px;
-webkit-border-radius: 6px 0 6px 6px;
-moz-border-radius: 6px 0 6px 6px;
border-radius: 6px 0 6px 6px;
}
Bootstrap 3多级下拉菜单
href="javascript:;">
下拉多级菜单
一级菜单
一级菜单
一级菜单
二级菜单
二级菜单
三级菜单
