The invention aims to provide a converter station firewall construction technology which solves the technical problems that construction efficiency and construction quality of a converter station firewall are improved. The construction technology includes the steps: performing construction for a firewall foundation; installing firewall formworks: (1) assembling composition formworks; (2) installing the composition formworks; casting self-compacting concrete: (1) transmitting the self-compacting concrete; (2) casting a self-compacting concrete firewall in a layering manner; maintaining the self-compacting concrete. The converter station firewall construction technology has the advantages that construction steps are simplified, construction quality is improved, and the strength and the safety of firewall structures are enhanced.