We first used oligomer polyamide resin as carbon source to prepare carbon dots (CDs) that can emit white fluorescence via one step ultrasound at room,temperature. We have had a further understanding in :the surface morphology and chemical characteristics of the CDs by performing TEM, XPS, XRD, Fr-IR, and Raman spectroscopy. It has been found that such carbon dots have good dispersion) low crystallinity, rich surface functional groups, and easy large-scale production:The quantum yield of the white fluorescent CDs was further enhanced from 3.3% to 28.3% by adding a silane coupling agent as a co-passivating agent and conducting ultrasonic treatment. We successfully prepared white-light-emitting diodes using these carbon dots as light conversion materials. To further broaden the applications of white fluorescent carbon dots, we employed the as-prepared CD solution as ink to prepare luminescent patterns, along with favorable versatile effect.