The present disclosure provides a testing apparatus for executing a test program, to perform a first test on a circuit component on a circuit board and a second test on the circuit board. The testing apparatus includes a first module, a second module, and a signal transmission line that connects the two. The first module includes a control unit, a signal generation unit, a signal processing unit, a signal expansion unit, and a power supply unit. The control unit generates a first control signal or a second control signal. The signal generation unit generates a current signal or a voltage signal. The signal processing unit generates a numerical signal. The signal expansion unit generates a second data signal. The power supply unit generates a working voltage. The second module includes a test address assignment unit that assigns an address and a signal isolation unit that performs noise immunization process.