The invention discloses a signal acquisition device for a relay protection testing device. The signal acquisition device for the relay protection testing device comprises a direct current sampling circuit, a current transformer, a voltage transformer and a synchronous signal acquisition circuit, wherein the direct current sampling circuit is connected with the input terminal of a DSP by virtue ofa signal conditioner and an A/D converter sequentially, the current transformer and the voltage transformer are respectively connected with the input terminal of a data selector, the output terminal of the data selector is connected with the input terminal of the DSP by virtue of the signal conditioner and the A/D converter sequentially, the synchronous signal acquisition circuit is connected withthe input terminal of the DSP by virtue of a phaselocking frequency multiplier, the output terminal of the DSP is connected with a photoelectric isolator by virtue of a pulse generator, the photoelectric isolator is connected with an upper computer by virtue of a communication device, and the upper computer is used for analyzing various acquired data. The signal acquisition device for the relay protection testing device has the advantages that voltage data and current data of the relay protection testing device are acquired and are sent to the upper computer by virtue of the DSP, and the upper computer analyzes the data, so that the relay protection testing device is verified, and working performance and stability of the relay protection testing device are guaranteed.