Recently, significant attention has been directed towards two-dimensional Janus materials owing to their unique structure and novel properties. In this work, we have introduced novel two-dimensional Janus monolayers, SZrAZ 2 (A = Si, Ge; Z = P, As), through first principles. Our primary focus was the investigation of the controllable electronic properties exhibited by the Janus SZrAZ 2 structures under the influence of strain and an external electric field. Our research findings indicate the dynamic and thermodynamic stability of Janus SZrAZ 2 (A = Si, Ge; Z = P, As) monolayers. In the equilibrium state, these monolayers exhibit properties of an indirect band gap semiconductor. When subjected to biaxial strain and an external electric field, we observed that the dependency of SZrSiAs 2 and SZrGeAs 2 monolayers on an external electric field is very weak. Their electronic properties can only be modulated by applying biaxial strain. For SZrSiP 2 and SZrGeP 2 monolayers, their electronic properties can be modulated under biaxial strain and an external electric field, resulting in a transition from semiconducting to metallic behavior. Finally, we calculated the carrier mobility of these four structures and observed that the SZrGeAs 2 monolayer exhibits a hole mobility of up to 597.52 cm 2 s -1 V -1 in the x -direction, whereas the SZrSiP 2 monolayer demonstrates an electron mobility of up to 479.30 cm 2 s -1 V -1 in the y -direction. In the x -direction, the electron mobility of SZrSiAs 2 and SZrGeP 2 monolayers was measured to be 189.88 and 528.44 cm 2 s -1 V -1 , respectively. These values are greater than or equivalent to that of experimentally synthesized MoS 2 (∼200 cm 2 s -1 V -1 ). Our research lays the foundation for utilizing two-dimensional Janus materials in electronic devices.