There are some problems such as complex circuit connection, inefficiency detection in digital circuit practical teaching. Hence, the research group has studied and designed a testing system of commonly used digital circuit chip. The system is based on NAND gate, phase inverter, data selector, counter, decoder and display decoder of the practical teaching. It is composed of upper system and hardware circuit. The upper system serves as entering, management, transmitting function table or truth table. The hardware circuit serves as receiving the signals to testing chip, providing result whether the chip gets damaged or chip’s function is normal, and showing the testing result. The system can reduce difficulty and complexity and improve the accuracy of chip testing in the digital circuit practice teaching. That is essential to conduct a correct experiment.