Through a low-cost approach, molybdenum disulfide (MoS2) transistors with polyimide (PI) dielectric layer that is more compatible with flexible electronics have been prepared, and microwave annealing (MWA) has been employed to enhance the electrical and photoelectrical performance of the device. The device, after undergoing a low temperature (135.6(degrees)) and short -duration (60 s) MWA process, demonstrates excellent electrical performance, with an OFF -state current as low as 5 fA, an ON -state current of 456 nA, and an ON/OFF ratio of up to 9.12 x 10(7). Additionally, a study on the photoelectrical performance of the device has been conducted. The device's responsivity (R), detectivity (D-& lowast;), and external quantum efficiency (EQE) were measured at impressive values of 807 A/W, 5.5 x 1010 Jones, and 2.2% x 103%, respectively. This work extends the application of PI as a dielectric material in 2-D optoelectronic transistors.