using UnityEngine.Networking;
IEnumerator LoadForWebRequest(){
	string fileUrl = "file://D:/Documents/Study/Assets/14/AssetBundle/ppp.assetbundle";
	using (UnityWebRequest request = UnityWebRequest.GetAssetBundle (fileUrl, 0)) {
		yield return request.SendWebRequest();  //发送等待回应
		AssetBundle bundle = DownloadHandlerAssetBundle.GetContent (request);
		Object player = bundle.LoadAsset ("Player");
		Instantiate (player);
		bundle.Unload (false);
	}
}

据说WWW要被抛弃了，没错就是UnityWebRequest替代了

使用UnityWebRequest.GetAssetBundle()发起加载AssetBundle请求

通过DownloadHandlerAssetBundle.GetContent()获取到AssetBundle资源