Mongod --dbpath error

Hello @zhao_qi, welcome to the MongoDB Community forum!

The image you had posted is the logging from the startup of the mongod process. You can open another console and connect with mongo shell or start the GUI tool like Compass and work with the database.

[EDIT ADD]

You can specify the logpath parameter to the mongod and the log data can directed to a log file - then you wont see it interactively.