The LaMnO3 film, Ni0.75Mn2.25O4/LaMnO3 supported bilayers and Ni0.75Mn2.25O4 film thermistors have been successfully fabricated through pulsed laser deposition (PLD) method. XRD analysis reveals that no chemical reaction occurs between LaMnO3 and Ni0.75Mn2.25O4 during deposition in the coexistence of bilayer materials. However, the resistivity at room-temperature of thin film with a Ni0.75Mn2.25O4/LaMnO3 bilayer is 19.6 Omega cm. It is much lower than the resistivity of the LaMnO3 (580 Omega cm) and Ni0.75Mn2.25O4 single phase films (94.2 Omega cm). Such feature is attributed to the existence of the parallel equivalent circuit in bilayer, the decrease in the grain boundary area and the increase in Mn3+/Mn4+ ratio. In addition, the electrical measurement shows that the thermal constant of the bilayer samples are almost the same as that of single layer Ni0.75Mn2.25O4 film. This study suggests that a bilayer concept is proposed to adjust the electrical properties of NTC thermistors. We believe the above results are very instructive for the applications and further research of Mn-based NTC oxides.