Data writing method and device

The invention provides a data writing method and device, relates to the technical field of computer security, and can prevent a main bootstrap program from being infected by malicious programs or viruses so as to ensure that the main bootstrap program can guide a computer operating system to be normally started. The method comprises the steps of obtaining first data to be written into a main bootsector; determining that the first data is data for modifying the main bootstrap program in the main boot sector; determining a feature code containing the first data in a preset white list; and writing the first data into the main boot sector. 本申请提供一种数据写入方法及装置，涉及计算机安全技术领域，可以避免主引导程序被恶意程序或病毒感染，从而保证主引导程序可以引导计算机操作系统正常启动。该方法包括：获取待写入主引导区的第一数据；确定第一数据为修改主引导区中的主引导程序的数据；确定预设白名单中包含第一数据的特征码；将第一数据写入主引导区。