A series of thermoplastic and optical transparent polyimide-bearing aliphatic rings were manufactured through a two-step approach. The solubility and melt processability were significantly enhanced after embedded with flexible thio-ether moieties. The complex viscosity was within 225.6-3980 Pa.s from 330 to 300 degrees C. The modified polyimide exhibited moderate mechanical strength to 76 MPa. The 5% thermal weight loss temperature was around 443 degrees C, with a glass transition temperature of 204.6-234.8 degrees C. Although the cyclic aliphatic segments endowed the obtained PIs with improved optical performance, the transmittance could be up to 82% at 450 nm, while the transmittance of industrialized thermoplastic polyimide derived from PMDA and ODA was less than 20% under the same condition.