2D twisted layered materials provide a new platform to study strongly correlated quantum phenomena. In homo- or heterostructures, the interlayer coupling is sensitive to the twist angles (θ), which serves as a key order parameter to controllably adjust exotic properties therein. The widely studied atomically thin molybdenum disulfide (MoS₂) shows strong photoluminescence (PL) and is considered a promising optoelectronic material. Herein, by applying a uniaxial strain up to 5%, the evolution of the Raman and PL spectra of bilayer MoS₂ with four different twist angles is investigated. The redshift per unit strain of the PL energy in twisted bilayer MoS₂ (tBLM) reaches its extreme when θ is 30°. Further, two kinds of phototransistors based on tBLM structures with twist angles of 0° and 30° are constructed. The photoresponsivity (R) and the specific photodetectivity (D*) of the 30°-twisted-tBLM-based phototransistor are successfully improved by ≈20 and ≈100 times than those values of the 0°-twisted one, respectively. These findings provide a beneficial understanding of the effects of twist angle and strain on the optical and electrical applications based on tBLM and are applicable to other 2D materials.