The invention provides a convertor station firewall construction technology. The convertor station firewall construction technology comprises the following steps of preparing construction and dividing a firewall into N layers in the height direction to perform construction, determining the number n of steel molding plates of each construction layer according to the construction layer number N and length of the firewall, wherein the firewall is divided into n standard steel molding plates from left to right to perform assembly and splicing, and the steel molding plates are manufactured on the basis; binding Mth-layer firewall steel bars; installing Mth-layer firewall steel molding plates; casting Mth-layer firewall concrete; dismounting the Mth-layer firewall steel molding plates; maintaining the Mth-layer firewall concrete; judging whether firewall main body construction is completed or not, and repeating the step of binding the Mth-layer firewall steel bars till the firewall main body construction is completed if the firewall main body construction is not completed. The convertor station firewall construction technology adopts the steel molding plate layered and sectioned construction operation mode, the turnover utilization rate of the steel molding plates is high, it can be ensured that the surface of the firewall is smooth, the steel molding plates are easy to splice and install, a construction period is short, and construction speed is improved.