As a key structural element, polyimides (PIs) are garnering attention as high-functional polymers in the microelectronics and optical elds. Recently, their structural behaviour renders PIs as promising candidates for the formation of charge-transfer complex (CTC). However, unfortunate drawbacks of PIbased CTCs are in their insolubility and low degradability. The endeavour to overcome the aforementioned issue is aimed at designing biodegradable PIs with high solubility. A novel organic diamine monomer bridges this gap. Based on these fundamental phenomena, we demonstrate an environmentally-friendly camphor aromatic diamine (CAD diamine). The efforts described herein shows excellent solubility and thermal stability by introducing two spiro moieties. Ultrafast degradable PIs were further prepared from CAD diamine, which not only prevented the polymer deterioration but also reported ultrafast degradability in a su cient manner.