Temperature-responsive drug delivery systems offer the chance to better deliver anti-tumor drugs to tumor cells in a more controllable condition. In this work, a novel temperature-responsive nanocarrier was synthesized by grafting allyl alcohol and N-isopropyl acrylamide onto a nanodiamond surface and conjugated with polyester dendrimer for the controlled delivery of paclitaxel and photo-thermal therapy under near-infrared light irradiation. The morphology, chemical structure, and properties of this polymer were characterized through systematic characterization analyses. The data obtained from the non-linear isotherm model indicated that the sorption procedure followed Langmuir isotherm. Adsorption kinetic data shown that the pseudo-second-order model fitted well with the experimental results. The in-vitro drug release shown that about 92.10% of paclitaxel release was found to be occurred at the simulated physiological fluid within 48 h (pH 7.4; T = 45 °C), whereas about 64.38% of paclitaxel release occurred at the temperature of 37 °C (pH 7.4). Also, the released drug under near-infrared light irradiation reached up to 97.34% over 15 min, achieving the on-demand paclitaxel release. The release of the drug from the nanocarrier followed the mechanism of non-Fickian diffusion and best fitted to the Korsmeyer–Peppas model. The nanocarrier indicated dose dependent cytotoxicity towards MCF-7 cancer cells.