An electronic device for updating on-board data of power off status is provided, which combines a rewritable memory, an embedded controller, and a second network socket onto a motherboard. The rewritable memory includes a target storage area. The embedded controller includes a second network interface electrically connected to the second network socket, for receiving a writing command and a binary file. After receiving power of a standby mode, the embedded controller executes a data writing program to receive the writing command and the binary file via the second network socket and the second network interface, and writes the binary data file into the target storage area of the rewritable memory by using the data writing program.