一般是：

scard0：指系统内部存储

scard1：指外插的sd卡

也有特例。。

分别获取路径的方法：

package com.main;

import java.lang.reflect.Method;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.os.storage.StorageManager;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;

public class MainActivity extends Activity {
	TextView tv1;
	TextView tv2;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		tv1 = (TextView) findViewById(R.id.tv1);
		tv2 = (TextView) findViewById(R.id.tv2);
		String str1 = getPrimaryStoragePath();
		String str2 = getSecondaryStoragePath();
		tv1.setText(str1);
		tv2.setText(str2);

	}

	private static final String TAG = "PhoneStatusBarPolicy";

	public String getPrimaryStoragePath() {
		try {
			StorageManager sm = (StorageManager) getSystemService(Context.STORAGE_SERVICE);
			Method getVolumePathsMethod = StorageManager.class.getMethod(
					"getVolumePaths", null);
			String[] paths = (String[]) getVolumePathsMethod.invoke(sm, null);
			// first element in paths[] is primary storage path
			return paths[0];
		} catch (Exception e) {
			Log.e(TAG, "getPrimaryStoragePath() failed", e);
		}
		return null;
	}

	public String getSecondaryStoragePath() {
		try {
			StorageManager sm = (StorageManager) getSystemService(Context.STORAGE_SERVICE);
			Method getVolumePathsMethod = StorageManager.class.getMethod(
					"getVolumePaths", null);
			String[] paths = (String[]) getVolumePathsMethod.invoke(sm, null);
			// second element in paths[] is secondary storage path
			return paths[1];
		} catch (Exception e) {
			Log.e(TAG, "getSecondaryStoragePath() failed", e);
		}
		return null;
	}

	public String getStorageState(String path) {
		try {
			StorageManager sm = (StorageManager) getSystemService(STORAGE_SERVICE);
			Method getVolumeStateMethod = StorageManager.class.getMethod(
					"getVolumeState", new Class[] { String.class });
			String state = (String) getVolumeStateMethod.invoke(sm, path);
			return state;
		} catch (Exception e) {
			Log.e(TAG, "getStorageState() failed", e);
		}
		return null;
	}
}

红米手机的效果：