The invention relates to a device update forecast system. The system comprises a computing apparatus and a database connected with each other, wherein the database stores N device information records;device information comprises a device ID, a deadline T1 used for indicating that a device must be updated, an update time threshold D1, a deadline T2 used for indicating that device depreciation expires, and a device remanent value rate r; and the computing apparatus scans the N records in the database according to a fixed frequency sequence, and provides device update forecast information for auser according to a scanning result.