action跳转控制器报错，刚用laravel不知道是哪里错了？请各位大神帮忙看一哈！

我是这样写的<form action="{{ action('UserController@showProfile')}}" method="post">；
报错内容：
MethodNotAllowedHttpException in RouteCollection.php line 219:
in RouteCollection.php line 219
at RouteCollection->methodNotAllowed(array('GET', 'HEAD')) in RouteCollection.php line 206
at RouteCollection->getRouteForMethods(object(Request), array('GET', 'HEAD')) in RouteCollection.php line 158
at RouteCollection->match(object(Request)) in Router.php line 823
at Router->findRoute(object(Request)) in Router.php line 691
at Router->dispatchToRoute(object(Request)) in Router.php line 675
at Router->dispatch(object(Request)) in Kernel.php line 246
at Kernel->Illuminate\Foundation\Http{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 52
at Pipeline->Illuminate\Routing{closure}(object(Request)) in CheckForMaintenanceMode.php line 44
at CheckForMaintenanceMode->handle(object(Request), object(Closure))
at call_user_func_array(array(object(CheckForMaintenanceMode), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 136
at Pipeline->Illuminate\Pipeline{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
at Pipeline->Illuminate\Routing{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 103
at Pipeline->then(object(Closure)) in Kernel.php line 132
at Kernel->sendRequestThroughRouter(object(Request)) in Kernel.php line 99
at Kernel->handle(object(Request)) in index.php line 54