A novel and efficient method for the use of non-edible cassava to synthesize biofuel precursors with long carbon chains in two steps was proposed. The finally produced precursors were based on the decomposition of cassava and condensation between furans and levulinates. The reaction parameters for levulinate production from cassava were optimized, and the results showed that the highest carbon mole yield of levulinates was up to 51.3% at 473 K, 4.0 MPa N-2 and 6.0 h. After that, precursors with yields of 88.0 and 90.5% could be obtained when the mole ratios between furans and levulinates were 1:1 and 2:1, respectively. Characterization of precursors using elemental analysis, C-13 nuclear magnetic resonance, gel permeation chromatography, and Fourier transform infrared spectroscopy demonstrated that different and intersecting routes of condensation resulted in the complex components of precursors. Moreover, the mechanism of condensation was proven to excessively depend upon the mole ratio between furans and levulinates in this investigation. This technical route indicates a simple and feasible method to produce renewable biofuel with long carbon chains from cassava directly.