An exemplary computer error detection device for detecting the warning sounds emitted by a malfunctioning computer is provided. The computer error detection device includes a storage unit, a display unit, a detection unit, and a processing unit. The storage unit includes a look-up table (LUT). The LUT includes a plurality of solution plans each corresponding to a predetermined warning sound. The display unit displays a selecting interface thereon for a user to input a basic input output system (BIOS) type or a computer model of the computer. The detection unit records a warning sound emitted from the malfunctioning computer and generates an electronic sample of the warning sound. The processing unit searches the LUT to determine a solution plan corresponding to the sample, and controls the display unit to display the determined solution plan.