Spectral characteristics preservation and high spatial resolution retention are two key issues in image fusion. Different applications may require different balances between the two issues. A new controllable remote sensing image fusion method based on wavelet transform was proposed. At first, the two images were decomposed into sub-images with wavelet transform. Secondly, these sub-images were fused in wavelet space based on their characteristics. Lastly, a fused image was achieved by inverse wavelet transform. By introducing the parameters, the balance between spectral characteristics preservation and high spatial resolution retention can be achieved at different levels. With some combination of the parameters, the visual effects and the statistical parameters indicate that the fused result is slightly better than, or comparable to, those of the commonly used image fusion methods.