In this work, we explore the electronic and optical properties of the SiH/γ-GeSe heterostructure using first-principles calculations, emphasizing its remarkable tunability under applied electric fields. Our findings demonstrate that the SiH/γ-GeSe heterostructure exhibits stability, indicating its feasibility for future synthesis. The SiH/γ-GeSe exhibits type-I band alignment and an indirect band gap, with optical absorption characteristics revealing enhanced absorption in specific energy regions, highlighting its potential for advanced optoelectronic applications. Under the influence of electric fields, the SiH/γ-GeSe heterostructure transitions to type-II band alignment and switches to a direct band gap, which significantly improves charge separation and light absorption efficiency. These findings underscore the versatility of the SiH/γ-GeSe heterostructure, positioning it as a promising candidate for a wide range of electronic and optoelectronic applications.