Multitarget medications represent an appealing therapy against the disease with multifactorial abnormalities─cancer. Therefore, simultaneously targeting son of sevenless 1 (SOS1) and epidermal growth factor receptor (EGFR), two aberrantly expressed proteins crucial for the oncogenesis and progression of prostate cancer, may achieve active antitumor effects. Here, we discovered dual SOS1/EGFR-targeting compounds via pharmacophore-based docking screening. The most prominent compound SE-9 exhibited nanomolar inhibition activity against both SOS1 and EGFR and efficiently suppressed the phosphorylation of ERK and AKT in prostate cancer cells PC-3. Cellular assays also revealed that SE-9 displayed strong antiproliferative activities through diverse mechanisms, such as induction of cell apoptosis and G1 phase cell cycle arrest, as well as reduction of angiogenesis and migration. Further in vivo findings showed that SE-9 potently inhibited tumor growth in PC-3 xenografts without obvious toxicity. Overall, SE-9 is a novel dual-targeting SOS1/EGFR inhibitor that represents a promising treatment strategy for prostate cancer.