The invention provides a testing device of a power sequence signal on a computer. The testing device comprises N input ends, N operational amplifiers, a processing unit and a display unit, wherein the N input ends are used for respectively receiving a plurality of power-on sequence signals from the computer, the N operational amplifiers are respectively connected with the N input ends and are used for regulating voltage of the plurality of power-on sequence signals, the processing unit is provided with N analog-digital converters and is used for converting the regulated voltage into N digital signals, and the display unit is used for displaying the N digital signals, wherein the N is an integer more than 5. As the testing device of the power sequence signal is utilized, a plurality of signals can be tested simultaneously, a test requirement of a mainboard power-on sequence signal can be met, testing strength is reduced, and testing work efficiency is greatly improved. The testing device provided by the invention has the advantages of simple structure, convenience for operation, and is capable of providing convenience for common skilled work personnel.