The invention discloses a three-phase high-efficient great-error electric energy detecting and calculating apparatus which comprises a three-phase electric meter check meter and a referential signal input module, wherein the three-phase electric meter check meter comprises a voltage locking module, a detecting and calculating module, a determination module and an output display module. The referential signal input module is connected with the voltage locking module, the voltage locking module is connected with the detecting and calculating module, the detecting and calculating module is respectively connected with an electric meter to be checked and the determination module, and the determination module is connected with the output display module. Only one-time prediction amount of a hand-operated input module or voltage prediction module of the referential signal input module is needed to input referential voltage signal data to the voltage locking module and to lock the data. The electric meter to be checked can be checked by using the data, and no real-time voltage value is needed during calculation. Original verification function is retained, wiring means is simplified to realize rapid measurement, and the work efficiency is greatly improved. Connecting a voltage wire is not needed, which means no connecting a bare part of a power supply. The safety level is greatly improved.