This disclosure relates to a three-phase electric energy measurement apparatus, comprising: a voltage detection unit for detecting voltage of each phase in power transmitting lines where the voltage detection unit is; a current detection unit for detecting current of each phase in the power transmitting lines where the current detection unit is; an electric energy calculation unit, connected to said voltage detection unit and said current detection unit, for receiving signals outputted from said voltage detection unit and said current detection unit, and performing signal processing and calculation, and then outputting a calculation result; wherein both said voltage detection unit and said electric energy calculation unit are connected in a star connection mode, forming a common virtual ground. Through the above-mentioned grounding manner different from that in the prior art, a three-phase four-wire electric energy meter is formed using a three-phase three-wire connection method. As a result, devices required by the three-phase electric energy measurement apparatus are saved, thereby reducing manufacture costs, and meanwhile, measurement errors due to asymmetrical loads of three phases are eliminated, thereby improving the measurement accuracy. Besides this, detection of single-phase current and single-phase voltage can be realized.