Activation of the stimulator of interferon gene (STING) has emerged as an exciting immuno-oncology therapeutic strategy; however, the first-generation STING agonists, cyclic dinucleotide (CDN) analogues, have suffered from many disadvantages and failed in clinical trials. Therefore, non-CDN small-molecule STING agonists are urgently needed. In view of the unique structure of the high potency of dimeric amidobenzimidazole STING agonist 5, a structural elaboration was conducted by modifying several structural hotspots of this scaffold. Triazole 40 was identified as a new potent STING activator, possessing EC50 values of 0.24 and 39.51 μM for h- and m-STING, respectively. This compound has a slightly better pharmacokinetic profile and is >20-fold more aqueously soluble than 5. It activated the STING signaling dramatically by directly binding and stabilizing all h-STING isoforms and m-STING. In vivo, intermittent administration of 40 was found to have significant antitumor efficacy with good tolerance in two mouse tumor models.