如何修改Matlab启动路径/Windows or Mac
控制台内输入一下两行命令，之后重启MATLAB即可
newpath = '你所要设定的路径';
userpath(newpath)
或者使用一下三种方法之一，windows平台下，方法二最为简单：
Changing the Startup Folder Via the userpath Function
Use the userpath function to change the startup folder as well as to add the startup folder to the search path upon startup. For more information, see the userpath reference page and MATLAB Startup Folder.
Changing the Startup Folder Using the Shortcut — Windows Platforms Only
To change the startup folder on Windows® platforms using the shortcut,
Right-click the shortcut icon for MATLAB and select Properties from the context menu.
The Properties dialog box for MATLAB opens to the Shortcut pane.
The Target field contains the full path to start MATLAB.
By default, the startup folder is DocumentsMATLAB; for more information, see Startup Folder on Windows Platforms.
In the Start in field, specify the full path to the folder in which you want MATLAB to start, and click OK.
The next time you start MATLAB using that shortcut icon, the current folder will be the one you specified in step 2.
You can make multiple shortcuts to start MATLAB, each with its own startup folder, and with each startup folder having different startup options.
Changing the Startup Folder Using the startup.m File
Use the startup.m file to specify the startup folder as well as other startup options—for details, see Specifying Startup Options in the MATLAB Startup File.
Reference：
http://www.mathworks.nl/help/matlab/matlab_env/changing-the-startup-folder.html
http://www.mathworks.nl/help/matlab/ref/userpath.html#btn2ix7-2