Graphene-based film heaters (GFHs) with laser-patterned electrode structures can be used in microheaters, thermal sensors, and thermostatic apparatuses for various high-value-added medical devices and creative products. To obtain uniform and higher temperatures, this study aims to design, fabricate, and measure GFHs with net-like electrode structures using ANSYS Workbench software, an ultraviolet laser processing system, and an infrared thermal imaging camera, respectively. The electric heating experiments (which were measured with an infrared thermal imaging camera) demonstrated that the temperatures of GFHs with net-like electrode structures were significantly higher than those of devices without patterned graphene films. Moreover, the temperatures of GFHs with net-like electrode structures increased rapidly with time when DC voltages higher than 12 V were applied for at least 10 s. A maximum temperature of 91.5 °C was obtained at 200 s when a DC voltage of 18 V was applied. Besides, minimal and maximal deviations of steady-state temperatures between experimental and simulated values were 6.9 °C and 10 °C under each corresponding DC voltage, respectively.