The invention provides a movable dietary investigation system, which comprises a server and a mobile terminal; the server comprises a signal receiver, a display module and a memory; the mobile terminal comprises a screen display touch control module, an input module, an operation module, a storage module, a database module, a food library module and a signal transmitting module; the server and the mobile terminal transmit data in a mobile Internet way. The invention further provides a corresponding use method, the method comprises the following steps of presetting food data by a system and calculating and grading the food data, after a user filling in dietary options, obtaining nutrient intaking amount through the database and generating a comparison curve with recommended intaking amount; and meanwhile, sending the message to the server to store and back up through the mobile Internet. The system supports self operation and is not limited by the space, after the options are input on site, the analyzing result can be obtained, thus, the data is prevented from inputting repeatedly; and the efficiency and the accuracy of the dietary adjustment work are improved, and both time and labor costs are reduced.