The two-dimensional heterostructures have outstanding physical and chemical properties that make them promising applications in nanoelectronic devices. A novel BC₆N/BN lateral heterostructure was constructed， and the structural stability， electronic structure， conductivity and volt-ampere characteristics of BC₆N/BN lateral heterostructure were investigated by the first-principles combined with the non-equilibrium Green's function. The BC₆N/BN lateral heterostructure not only exhibits dynamic stability but also possesses a direct bandgap of 2.01 eV， static potential difference generated at heterojunction interface， electrons and holes form an electrical barrier at the interface. Compared to the BC₆N and BN monolayers， the conductivity of BC₆N/BN lateral heterostructure is significantly reduced and exhibits strong anisotropy. The volt-ampere characteristics of the BC₆N/BN lateral heterostructure show that almost no current is generated in the voltage range of 0 to 2.5 V. After the forward voltage exceeds 3 V， the current shows a linear increase trend； during the process of increasing the reverse voltage from 3 V to 5.5 V， there is only a weak current. When the reverse voltage exceeds 5.5 V， the current increases nonlinearly. Therefore， the BC₆N/BN lateral heterostructure has anisotropic conductivity and unidirectional conductivity characteristics， which can provide the important theoretical basis for the design and preparation of nanoelectronics devices.