In order to solve the problem that a traditional microcomputer protection device cannot quickly and effectively take appropriate protective action to an apparent fault when a power system is restored, this paper introduces research on a new type of microcomputer protection device. First, the battery is used on the hardware to supply power to the whole microcomputer protection device when the power system is cut off, and the pulse output is controlled to charge the tripping capacitor, and the capacitor voltage monitoring circuit is used to ensure that the voltage reaches the critical voltage of the driving circuit breaker at all times. In addition, two algorithms are designed on the software. A “fast algorithm” is suitable for the system power failure recovery time algorithm, to ensure that the power failure recovery moment fault can be quickly cut off. Another “accurate algorithm” is applied to ensure the reliability of the whole device in normal operation. According to different situations, different algorithms are used to form the protection algorithm of the new microcomputer protection device. The experimental results show that compared with a traditional microcomputer protection device, the new microcomputer protection device can cut out the apparent fault existing at the moment of power system power failure recovery in a shorter time, and does not affect the reliability of the protection action in normal operation. This work is supported by National Natural Science Foundation of China (No. 61505001).