In this manuscript, we report low-temperature spin spray deposited Fe3O4/ZnO thin film microwave multiferroic heterostructures that show strong magnetoelectric coupling. Static and microwave ME interactions were observed in the Fe3O4/ZnO multiferroic heterostructure. A clean, void-free interface without inter-diffusion was observed by high resolution TEM imaging. Large voltage induced effective magnetic field of 14 Oe was realized at a low voltage of 20V through voltage induced in-plane ferromagnetic resonance field shift in the Fe3O4/ZnO multiferroic heterostructures, which is much higher than other strain-mediated thin film multiferroic heterostructures. Compared with most thin film multiferroic heterostructures prepared by high temperature (>600C) deposition methods, for example, pulsed laser deposition, molecular beam epitaxy, chemical solution deposition or sputtering, these Fe3O4/ZnO multiferroic heterostructures have much lower deposition temperature (<100 C) at a much lower cost and less energy dissipation, which can be readily integrated in different integrated circuits.