A new convenient procedure has been carried out for the production of diesel distillates assisted by modified sulfated iron oxides under mild condition (298 K and 1.01 MPa). The products successfully obtained by this method are mainly long, linear hydrocarbons from C-13 to C-24, all of which can be used as diesel distillates. Correlation of the catalytic performance to the structural properties is also discussed by a Fourier transformation infrared spectrometer (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The experimental results showed that the addition of a different modifier to sulfated iron oxide can affect the performance of catalysts and may be due to the different strength of acid, dispersibility, crystallization degree, crystal particles, and ratio of deprotonated and protonated S element. In comparison to the reaction processed in the high temperature and high pressure, this process became rather easy with a simple operation, lower energy consumption, and environmentally friendly.