System, method and device for uploading files

The embodiment of the invention discloses a system for uploading files. A method for uploading files comprises the following steps: carrying out integrity checking on a to-be-uploaded file by using a user terminal to obtain a first check value; dividing the file into a plurality of data packets which are divided into groups; sending a file uploading request to a server; sending the data packets in the groups; sending a group uploading completion prompt when the server receives all the data packets of the groups; if the user terminal does not receive the group uploading completion prompt, sending a request message; passing the subpackage numbers of unreceived data packets back by the server according to the request message; re-uploading corresponding data packets to the server according to the subpackage numbers by the user terminal; after the file is successfully uploaded, carrying out integrity checking on the file by the server to obtain a second check value; and when the first and second check values are equal, determining that the file is fully uploaded successfully. According to the embodiment of the invention, the file uploading success rate can be improved, and unreceived data packets are re-uploaded in real time, so that the file transmission integrity is ensured.